I have Armored tracks paired with Hardened tracks. For some reason, Sleipnir is slightly higher that Hardened, so after replacing Hardened with them, the car becomes unstable, it rotates in place for no reason and slips from surfaces because the tracks only touch the ground at two points.
Is this a bug, or intentional to make Armored tracks incompatible with Sleipnirs?
I believe it to be intentional, though likely not for the reason you suggest.
While I understand your frustration, some of us like having different height options with builds. While being able to set the suspension height in the garage would be optimal, in lieu of that, this gives us some option for change.
You might be able to fix the handling issues by spacing the two track types apart a bit further.
The tilt could be useful for some builds, so thanks for pointing it out.
This is a feature. Sleipnir problems are fixed by getting more Sleipnirs. What to do with the extra ride height and other benefits of Sleipnirs?
How about:
Go over higher terrain.
Shoot Porcupines from high up and hit hovers.
have your guns perched higher to avoid being hit by firedogs.
Stash vulnerable parts of your build in the empty space under the Sleipnir.
Go faster than lame Hardened Tracks.
Have better tonnage than lame Small Tracks.
Have extreme fire resistance.
Throw some turret cannons on them and increase rotation speed with the new perk.
Maybe all of the above. Sleipnirs are good. Replace Hardened tracks. They are bugged Sleipnirs that ride too slow and low to the ground.