I made a test of warp groups on a medium complex group with lots of elements with FX. The pleasing snappy performance of Affinity is totally gone here, I have an M1 equipped Mac, but the adjusted perspective is rendered like in the old computer days. That being said it was perhaps not a completely fair test, but a bit surprising though. I just sat there looking at chunks of rendered objects appearing second after second. I hope you expect to optimize this in the future.
My thought was therefore that I should go into wireframe view mode to adjust the perspective there, so I wouldn't have to sit and wait for the render, trial by trial for the right perspective.
It doesn't work at all. I see no result from my changes.
So I try to open more simple files. But I see nothing but a perspective frame in wireframe mode when I want to edit a warp group.
Is that the case? Then I am are bound to edit the perspective in normal mode with slow performance. I use wireframe mode often when I am dealing with complex drawing - I do that most of the time.