Changing time signature of one bar only...

…and having the changed bar reflect in the number of beats it has the new time signature.
Re https://www.steinberg.net/forums/viewtopic.php?t=104643

I’m working on an organ transcription right now and am changing time signatures constantly. How do I change the time signature of one bar only and have that bar’s beats reflect the new time signature?

I"m sure there is a way, but I have not been able to find it, yet. Thanks, all!

This is potentially awkward.
It works well if you need to lengthen a bar: if there isn’t one, add a time signature at the beginning of the bar that follows the one you’re going to alter, then activate insert mode and add the new time signature at the beginning of the bar in question. Dorico should add as many beats as needed and shift everything else accordingly.
If you need to shorten a bar, again, add a time signature in the following bar if there isn’t one. Now add the new time signature in the bar you need to truncate, then delete the small extra bar with shift-B and –1.

I hope this helps!
Florian