Hello messyhead,
the point "Fix KA-50 cockpit lighting" should be renamed to "Fix all helicopters cockpit lighting" because non of the helos have a cockpit illumination in 1.16.0 Fix1.
Only the MI-28 has different textures for day, dusk, night.
Compare it with 1.15.4. Here every helicopter has a cockpit illumination (even the MI-28 additional to the three texture sets), to see what I mean.
It's not so noticeable in the US choppers in 1.16.0 because they have less steam gauges and big MFD's, so the dark cockpit isn't very eye-catching at the first moment, but the cockpit lightning is definitely missing in all helicopters.
Cockpit lightning in 1.15.4 must be something like a helicopter independent 3D feature which is defined in the game code itself.