From what I've read, this is basically correct. It can apparently add about 3 stops of extra highlight retention.
On most modern cameras, changing ISO doesn't change the sensor gain unless you move into the territory that is handled by the next "native" ISO. The only exception I know to this is Z Cam (which is why they suffer some WB shift when changing ISO). Otherwise, for raw codecs, you are adjusting the allocation of stops/highlights in the recording - and for non-raw codecs, you are changing how the camera post-processes the raw that it read at the base ISO.
So in theory, the LOFIC should help with any ISO that is set by the user.
It should also be understood that it only helps with highlights and does nothing whatsoever for shadows - meaning that ETTR is probably even more of a thing with any LOFIC system than it was with most Bayer sensor setups.