Without code behind, with a conditional formating changing the Visibility, to avoid empty space in the final report, the control must have its Height put to 0. But then it isn't visible anymore in the designer.
With a DesignHeight, it could be still visible in the designer.
The other solution would be to be able to change the Height in conditional formating.

When using report templates, the only connection with the original template is when the report is created. This is problematic due to the time it takes, as well as the potential for error and inconsistency.

It would be helpful if the report designer included an ability to update a report based on the template. If a minor change needs to be made to a group of reports, now that change has to be done individually in each report. Ideally there should be an option to update the report from the original template. While I understand that detailed content would be problematic to update, things such as styles, report and page headers/footers, etc., could be updated (or 'replaced' with the equivalent content from the template). 

Ideally there would be an option to update from template, and then the user could select which items to update; 
- styles
- page header/footer
-report header/footer

I like how with Kendo UI for MVC you have the option of placing the references dlls into lib/kendouimvc, so projects are not dependent on having the correct version installed (or having the telerik control panel installed on a build server), and when updates occur it will copy over everything and make sure you don't miss something. 

It would be nice to have an option in the upgrade wizard extension thingy to have a section for including telerik reporting and it will put the necessary dlls in your project the same way.

I can easily manually copy the files over, so this is just a pet peave thing, but it would be nice...

Possibility to select BarCode Encoding based on value on record dataItem.

I am using Telerik Reporting with MVC 5, and would like the ability to use the custom parameterEditor with MVC. If anything, I'd like to be able to create it with razor MVC, and then use jquery to add the parameterEditor.

It would be nice to have an image filter option when exporting reports to PDF. For example we need to export an image to PDF using the "Flate" algorithm so that the image is not compressed in any way.

To be able to change the branding from Telerik to our own company or product specific banding. For instance MyApp Report Server with own images.

I would like to see a control as in an addition to the kendo mvc toolkit where you could build into an application the ability for customers to design the layouts of their reports.  For example.. Say you have an app you built for multiple customers.  Now the app might have a series of basic report templates in terms of queriable object model outputs. Being able to build an interface that would allow the customers to design their own layouts for what fields, positioning on the page etc..labels etc. and save that design to their account for future consumption would be a huge selling feature for an application. 
Specific example an invoicing application.  Well you could pre build a bunch of templates and have the customer choose one (the only real option currently available)...or you could provide a list of fields(based on object models for the underlying report query) and have an embedded designer allow them to design their own invoice and save it.  

At present one cannot have a subreport in report header/footer. This is such a limitation 
e.g. you have a company header which you want in every report. Normally what you expect is to make a subreport and include that in header of other reports. So if you change any details you can edit that subreport and it get reflected in all other reports. But unfortunately you have to include the company header in every report not only the controls but also in the datasource.
I used to develop in MS Access back in 90s and even then its reporting has this feature as standard.
So come on Telerik 

Having a white background in a view when using the dark theme is very bad for the eyes.
You should check all your UI in Visual Studio, as I already asked in the past for a correct context menu for dark theme (now done).

Currently, the size and location of items displayed in Properties view are rounded value, but the real value written in the .Designer.cs isn't rounded at all.

This created some imprecision in size and location, possibly resulting in unwanted resizing of the report width, or in overlap.
Now, it is only possible to correct this in .Designer.cs, and the user don't see the problem without zooming at maximum or opening the .Designer.cs

Rounded value seems better than some unneeded decimal, but then the value displayed should also be written in the .Designer.cs

When selecting several items, it should be possible to change the size and location of all of them, at least if the values are the same

1.  To add box plot chart feature which shows Statistical Five Number values: Median, Q1, Q3, Min and Max.
2.  To support Points Jitter which shows points of a data set (which are used to calculate Statistical Five Number) on same chart.
3.  To show label on X-Axis of the grouping.

Add the functionality of the Page Up/Down as well as Home and End to the WPF Viewer Control, so that the displayed page may be controlled using the keyboard.
These buttons should also work with the CTRL+ variations.

Datadynamics was purchased by GrapeCity some 4 years ago but Telerik Reporting is still relying on the old assemblies for converting.  The converter needs to be updated and should support rdx as well as codebehind files.  I was able to convert the Telerik.ReportConverter.ActiveReports to use ActiveReports 7 but am not able to use the modified dll.  See attached.

As reports are commonly based on dates, some means of doing date addition and subtraction would be beneficial.

Make the F5 key (refresh) in the Report Viewer programmatically controllable by using events tied to the viewer.  For example, I want to disable the F5 refresh functionality and add my own functionality when the F5 key is pressed.  I currently have the ability to disable the refresh icon (ShowRefreshButton=false), but not the F5 key button.

Would it be possible to prioritize which characters can "Break" when wrapping text inside a text box?  For example "foobar/foobar" will not break at the slash, it'll instead break at the character that hits the width limit. It would be my suggestion that punctuation be prioritized for "breaking" before all other characters, in the event that there is no space.

In the attached example, the column headers are dynamic (localized), and there's no way to predict what the text will look like (in whatever language)... Though I accept that no matter what, a string longer than the textbox width will need to break somewhere, I'd prefer that you break on "better" characters if they are present.

(Pretty nitpicky, I know, but this would save me trying to code the logic into an expression or function... which could prove complicated due to variable width of fonts)

When using the Report Explorer, the tree automatically expands to all levels expanded, on making any change to a Property for the currently selected item.
This makes using the Report Explorer very frustrating, so you end up shouting at the window to 'Stand Still!".