Basically: some parts of X-Plane take measurements of real world information and attempt to simulate them. I have previously referred to this as "reality-based" simulation (e.g. the goal is to match real world quantities).
In those situations, if you intentionally fudge the values to get a particular behavior on this particular current version of X-Plane, it's quite possible that the fudge will make things worse, not better in the future.
This came up on the dev list with the discussion of inside vs. outside lighting. X-Plane 9 gives you 3 global lights for objects in the aircraft marked "interior", but none for the exterior.
Now there is a simple trick if you want global lights on the exterior: mark your exterior fuselage as "interior" and use the lights.
The problem is: you've misled X-Plane. The sim now thinks your fuselage is part of the inside of the plane.
This might seem okay now, but in the future X-Plane's way of drawing the interior and exterior of the plane might change. If it does, the mislabeled parts could create artifacts.
So as a developer you have a trade-off:
- Tweak the sim to maximize the quality of your add-on now, but risk having to update it later.
- Use only the official capabilities of the sim now, and have your add-on work without modification later.