There was a studio request a few years ago for this, link here, but I was wondering if there are any plugins or something similar that could do this.
Explicitly to resize unions, not to my knowledge. You’ll have to set the property manually or use a tool that strictly only resizes along a selected axis.
I’m not sure of the current efficiency but I have previously tried to make unions stretchable in my plugin.
It resulted in too many triangles from the simplest of stretches and wouldn’t create the Union as a result (exceeds limit).
This was a year ago though, and the new CSG is probably more efficient with triangle-count minimization.
To stretch a Union, first seperate the union out into it’s constituent part’s (and negative parts). Group them in a model next and then perform the stretch. Finally, attempt to re-union it all.
I don’t use any plugins for stuff like this, I usually export the union to .obj then import it into a mesh.