I just had a look at this and when both tools are turned on and preview deltaE is active the mask shown looks off, but Iâm not sure what to expect when doing this.
The tools are doing the correct thing based on their individual masks, though!
Iâm not sure if this is as designed or an actual bug to be honest.
In my workflow, if I apply multiple tools to the same spot, and these tools have individual Scope sliders I always turn off the other tool(s) to dial in that specific Scope.
Each scope has its own target and turning them all on when dialling in using Preview deltaE just sounds wrong to me. I really would not know what to expect when multiple masks are shown at the same time. Maybe give each scope (group) its own colour?
The again, Iâm not one of the RawTherapee developersâŚ