[Gimp-user] Transform tools in 2.10: independent window back to on-canvas dialog

[Ofnuts <ofnuts gmx com>]

In the 2.10 transform tools show an on-canvas window (a bit like the 
text tool in 2.8). This window can be made an independent window by 
clicking on the up-arrow icon.

So, is there a maneuver to make that independent window become an 
on-canvas widget again, without either 1) restoring to factory settings, 
or 2) editing the "sessionrc" file? I tried several drags without success.