I've implemented the proposed fix (thrower has terrain check on frames after projectile leaves hand and becomes faller if terrain is removed) in commit e8f8065. I did experiment with removing the shrugger, and while it's still perfectly possible to chain throws (thanks to skill queueing), it just feels awkward how quickly they revert to walker. Extending this would introduce an edge case where the thrower can only be assigned certain skills once it's past a certain frame in its animation, and this feels even worse. Keeping the shrugger feels nicest, ultimately.