garageCube

Digging through the forums, I found that you can adjust the perspective of a group by alt or option clicking the group quads on the output end of things (as long as "mesh warping" is turned on for the group). Great!

The group seems to also allow mesh and bezier but when I click to use those features (I.e., add warping point) it clicks down to the quad within the group at the location of the click - it doesn't seem to allow mesh or bez warping on the group quad. Am I correct in this?

Also - have found out that sometimes the option / alt click doesn't work. To re-enable it just toggle mesh warping off and then on again for the group.

Mesh Warping is not enabled on groups. Groups are mostly a way to organise file. Their geometry isn't stored but MadMapper keep their perspective transformation. They also hold opacity and color levels, which will be combined when rendering child surfaces.
Indeed Warping settings should only be available when a single quad is selected (and not its parent group)

Makes sense. I'm having a hard time figuring out how to reliably perspective warp a group. Sometimes alt/option works and sometimes it doesn't. Is this a bug?

Alt+drag handle works on "shadow group" (free multiselection) or on a "surface group" (visible in the stack) when perspective setting of this group is enabled. It won't work if the group contains a 3D surface.