I wish I was a programmer so I could try and make this improvement...
When dimensioning a radius or a diameter, I don't like that the diameter dimension is always put at the center of the circle. It's a big problem when you have two or more overlaying circles. Likewise, the radius dimension defaults to inside the arc. It would be nice if you could have the dimension numbers inside the circle or arc if you kept the mouse pointer inside the object but you could have the dimension number outside of the object if you drag the mouse pointer outside of the object kind of like how the Horizontal, Vertical, Linear, Aligned dimensions work. Even better, a general upgrade to all dimensioning would be that you drag the mouse pointer to the place where you want the dimension number to appear and LibreCAD added a Leader line to the dimension line or object as needed. These couple of things are the biggest weakness that I've dealt with in LibreCAD. Dimensioning often takes me at least three times longer because I do a quick general dimensioning with LibreCAD's default way of doing dimensions then I go back and clean up all the ill placed dimensions by replacing them with Leader lines and Text.
Select an existing dimension by clicking on it. It gets marked and there will be a small blue square at the dimension text. Grab it with the mouse and pull it to your desired position.
If you also want the dimension line at a different position just use Horizontal, Vertical, Linear, Aligned dimension instead. Works satisfyingly depending on Snap on Endpoints and Snap Middle set.
OK. I just tried it and, like you stated but I didn't quite understand until I tried it, it only moves the dimension number out of the circle. I still have to add Leader Lines from the new dimension number to the circle or radius. So it is only about 20% of what I was hoping for.