Thanks everyone for testing. I've created the issues for those problems, and will make sure they are addressed before we merge this into bleeding edge.
As we found out, the solution we implemented before was not good enough for all use cases. The virtual/dynamic attributes are fine in most cases, but sometimes we need even more flexibility. So we implemented yet another enhancement in this area -- full-fledged packs per combination.
You can now choose between two different versions of packs
Pack of existing products -- original implementation, when pack is defined on product lavel. You can use virtual/dynamic attributes here to tweak pack content using dynamic product attributes, as described in this thread above
Pack of existing products - combinations -- new functionality. When you select this, you won't be able to define pack on product level, but you will have to define packs for every combination separately. This gives you great flexibility, as your combinations can have totally different/independent pack items. But obviously, it will be more complicated to set up, as you need to define pack content for every and each combinations. So choose this only when appropriate
Pack content on combination level:
This new functionality is in pack-combinations branch.
If you can, please help us with testing once again.