Got inset to work here, after the rotate was done. (Twist command not used.)

Here is the rotated box before inset:


Well, the rotated box has to be saved and reloaded, before the inset command works.
(based upon limited testing.)

Hi plish, also it looks like another way you can do it with your previous "twist first" method is to delete the top and bottom faces after you've done the twist and then select the now open-ended twisted box and use Construct > Planar to close off the ends with brand new planar end caps.

Probably after that the Inset will work - basically what happens is that after you do a control point manipulation on an object all surfaces that make up the object are converted from any "analytic" surfaces (specialized surface classes for specific shapes like spheres, cylinders, and planes), and instead become just a generic NURBS surface. But some processes like offsets work better when they can use analytic surfaces when possible. Deleting and putting new end caps on will make the ends to be analytic planes and that will help, and also saving the file and reloading it will cause them to become analytic surfaces as well.

I can probably fix this up so that after you do some control point manipulation any things that are planar after the point squishing can get set up with analytic surfaces again instead of those being lost as part of the control point editing process.

- Michael

Thanks everyone for the input. Great education, appreciate it!

Michaels planar re-creation to get an "analytic" face works on a twist command twisted rectangle.
Just the last selected face direction required it. The twisty sides would do inset, as well as the bottom side.
Sometimes the inset would be "outwards," when it should have been "inwards," on the bottom side.
(Like "inside" and "outside," were backwards...?)

Thanks for the info!!

I've fixed this up for the next v3 beta so that after control point editing it will now automatically test for and use analytic surfaces when possible in the result, so the inset case here that failed should work in the next v3 beta without needing to do any extra steps.

Thanks for reporting the bug!

- Michael

You're welcome!

Thanks for the quick fix, Michael!!

plish