>>342483274
Normally if it boots you out, it's because the spawn position is set improperly. Two things to note: 
The world descripter's respawn height value should be fine as is. It's not relative to the object or spawn, but an absolute Y value. Leaving it at -100 is fine.
What I do is I set a cube or something without a mesh as a spawn wherever I need it to be. You don't need it to be a cube, it can be empty, but having visuals (until you remove the render component from it) is nice enough for lining it up so it sits on the ground. Also remove the collider.