Issue type:

➕ Feature request

i don't know how easy/hard it is to detect inventory slots that hold only the value of an item, rather than holding an "actual" item, but if that's relatively easy, please would you consider detecting and allowing writes to those types of slots?

Sounds like an interesting use case.
This is however very difficult to support, as all mods expose only real slots via the item handler interface from Forge.

This would require introducing something like a fake item handler (probably in common capabilities), and adding support for all mods that have fake slots.

yikes, i shoulda known i was asking for the moon on a string, sorry! a thought (perhaps way off-base) about support in other mods - maybe successful PRs to (f'rinstance) immersive engineering & industrial foregoing would get the ball rolling and help other devs see the light and add support for your fake item handler API?