I would like to prevent the user from entering certain characters. At the moment, the closest feature is using validation to inform them of invalid input after the fact, but I'd like to prevent them from inputting it in the first place. Being able to define my own rules like in React (see the second example here) would be nice.

When the user enters a value, clicks out of the Masked Textbox and then back into it, the cursor is placed at the beginning of the input rather than at the end of the value.

This issue only happens when:

• The MaskedTextBox does not have a mask specified.
• The MaskedTextBox does not have an initial value.

Reproduction: https://blazorrepl.telerik.com/meEpmEbR20id24Ss02.