The test3 files work almost perfectly except "Enter Alkesh", which puts you under the ship and you fall. It's not far below the ship, though. I can't tell if this has something to do with the odd elevations and slopes of the Alkesh decks or what.
The rings inside the ships are visually in precisely the correct elevation relative to the deck. Looks great.
Also, the "almost" in "almost perfectly" is because the activate and deactivate autopilot hold for ring transport actions are hard to find. They appear reasonably consistently in third person view, but not always, and I couldn't find them at all in first person view or in a #6 menu check (just in case). I know there's not much you can do about actions, so it's liveable, just thought I'd mention it in case you have some fancy thing you *can* do about actions.
And, since I'm mentioning everything, the "Get Out" function for both ships does an odd thing, causes an odd bobble - it could just be that you're putting the unit a tad too high and it falls a bit, but it also might be a facing issue with respect to nearby furniture. If you force the unit's facing to be ship's heading, that might keep one's weapon from interacting with the furniture, and if you lower the "Get Out" relative elevation by, I don't know, maybe 0.2 m that might reduce the bobble. (This happens very quickly, so it's hard to be precise.)
Making good progress!