Basically what the subject says. I invested all the focus I was saving to unbind Void Flow into Inner Might in the Zenurik focus tree as I thought it would make heavy attacks functionally free in conjunction with the Focus Energy mod.
When I went to test it in the simulacrum, though, Inner Might didn't seem to do anything.
I turned Inner Might off, and tested again, it did nothing.
Turned it back on, seemed to do nothing.
The build I was using did have Focus Energy, so I decided to try replacing that and see if it was somehow overriding Inner Might's bonus, and after testing I confirmed no, it wasn't. Inner Might just seems to, well, not do anything..
Another weird thing is the description, "Increase Heavy Attack Efficiency by 60%", which doesn't seem to be terminology used anywhere else. Other mods say "Combo Efficiency" for what is seemingly that effect, which makes me think that Inner Might may have been passed over early in the rework when that was the term being used and may not have properly had a function assigned to it.