@rlorenz
Yes I said that with a bit of a reservation.
Since a mission like this would be a first in many ways, and one not the least important that it would be for traveling over a surface / liquid we do not know much about - or hardly anything! So the amount of methane / ethane might indeed be one such showstopper.
Here on Earth we use hovercrafts where conditions vary, and on Titan tholin foam could be problematic.
So I did favour the hovercraft by mentioning since it would overcome the problem that paddles or one propeller working in liquid might have. Being able to travel over various surfaces. Subsurface hydrocarbon could pose a threat by grounding the vehicle. Imagine the camera on this craft on Titan only seeing a perfectly clear surface but might risk getting stuck on such subsurface ice.
And again in favour of the hovercraft, it could potentially continue past the lake and study other locations and materials on one extended mission.
Oh yes I have experimented with liquid nitrogen also, one of us thought it might risk damaging the floor, but for the very reason you pointed out, it crates a cushion of gas so it do not actually touch the floor.
Bottom line is that it might not be practical, even with the low surface gravity.
But I do think that one having one active secondary propeller or turbine to crate lift complicate any design and a risk of a breakdown.
And not the least important, the power requirement for one such would make it unfeasible from the start.
So no I did not envision anything like this one for a Titan mission.