If I understand correctly, immersive mode make it so when you have an inventory open or any menu, it does not "unlock" the cursor like it would usually do.
For example:
- Immersive mouse OFF: I open my inventory. The cursor get unlocked and I can move it and use my inventory.
- Immersive mouse ON: I open my inventory. The inventory is on the screen but my mouse cursor still control my character and I have to press and hold the "Lock/Unlock Mouse Cursor" to be able to use my inventory.
It is that holding to move the cursor that we'd like an option to toggle. I personally love immersive mouse, but I absolutely do not want to hold it all the time while I move stuff in my inventory. I'd much rather have a toggle.
So what we want is an option to enable toggle of "Lock/Unlock Mouse Cursor" similar to the option to enable toggle of sprinting.
EDIT: That said, if you say that it could possibly be done with a macro, it'd be helpful if you could write how we could do it. Never touched the macro function but I would be interested in knowing.