Hello, this is quite an old issue and one that our customer has been frustrated with but no indication that it is planned at any point. It seems like this should be standard behavior. I tested a small change to your source code that allows multiple key matching as requested here. Would you be willing to incorporate this in the next release?

Changes to TelerikDropDownList.razor.cs:

New code:

private DateTime? lastHighlightKeydown;
private string cumulativeHighlightText;
private const int HIGHLIGHT_TEXT_THRESHOLD_MS = 400;

private void SetCumulativeHighlightText(string value)
{
    var now = DateTime.UtcNow;

    cumulativeHighlightText = !lastHighlightKeydown.HasValue || (now - lastHighlightKeydown.Value).TotalMilliseconds > HIGHLIGHT_TEXT_THRESHOLD_MS
        ? value
        : cumulativeHighlightText + value;

    lastHighlightKeydown = now;
}

And modify the existing JS interop callback method for keydown:

public async Task DropDownList_KeyDown(string shortcut)
{
    switch (shortcut)
    {
        ... // same as existing code
        default:
            SetCumulativeHighlightText(shortcut);
            await HighlightItem(cumulativeHighlightText);
            break;
    }
}