"Up" Ion Thrusters exert Down force in atmosphere at low thrust output values

I'm using this vanilla blueprint for testing, but the same effect appears to happen with all ion thrusters, even modded thrusters: https://steamcommunity.com/sharedfiles/filedetails/?id=1988066571 First noticed that some ion thrusted blueprints seem to fall out of the sky, even if they have more than enough ion thrust to overcome gravity. To recreate:

1. Paste blueprint into world
2. Turn all Ion Thrusters OFF
3. Verify grid hovers at 0kph on atmo thrust only
4. Turn all Ion Thrusters On,
5. Verify grid still hovers at 0kph
6. Select all "UP" Ion Thrusters and apply Thruster Override at a small value (100 kN, for example)
7. Notice that grid accelerates DOWNWARD
8. Continue Increasing Thrust override value.
9. Note that at some point, grid stops downward accel and begins upward accel.

The effect is worse with modded thrusters that have higher max thrust values (like the T4 engines from the Tiered Engine Superpack: https://steamcommunity.com/sharedfiles/filedetails/?id=642589539&searchtext=tiered+engine Replacing vanilla Ion thrusters with modded thrusters will cause some grids to slowly lose altitude, rather than hover. If I had to guess, I would say that there is some line of code that attempts to compensate for ion thruster inefficiency in atmosphere by using something like

ionThrusterOverriddenOutput -= ionThrusterMaxOuput * 0.3