It seems that there are a lot of questions from people who do not realize that a tool needs to be activated for it to work and who don’t (at first glance) understand that a circle before the tool’s name means it has not been activated.
Perhaps having the name of the tool in lighter, greyer type until it has been activated (in addition to the little grey circle) would help.
Yes I know people should read the manual, but. . .
Please do not file bug reports or feature requests here.
For more info, read
@RichardRegal GUI changes: highlight enabled modules, RawTherapee theme CSS clean-up, minor tweaks by Thanatomanic · Pull Request #5929 · Beep6581/RawTherapee · GitHub
Please join the discussion there and let me know what you think.
Is it difficult to compress the overall height of the active window by closing the gap between the sliders, etc. and to decrease the height of the active blue bar?
Thanks. I have done so and posted a comment there.
I also wrote a comment. Thanks @RichardRegal for bringing this up and @Thanatomanic for following up. 
Which I had checked before posting, and could not see where to make feature requests. Even the link task pointed to as “Report bugs and make feature requests” only deals with bug reporting and pretty much all of that is what the report should look like.
No problem. I am merely repeating the maintainer’s desire. To ensure that your bug report or feature request is known and addressed, users should submit them or add comments to GitHub.
If you wish to post here, that is fine; but also contribute to GitHub. I and other users have been told this many times; so now I remember to do both, even though I love to post here first too.
That said, @Thanatomanic, @heckflosse, etc., are so friendly and willing to engage here. So do whatever you think is right and less frustrating.