I've got a couple of cups like that. The bases are usually very thick which shifts it's center of gravity lower. It's not nearly as top heavy as they look
I love mine! The front plate has hinges so it folds down and outta the way. When I’m not using my key board I can hide it and leaves desk open for mouse and snacks
IIRC the thing that causes long term damage is staying in the same position for long periods of time. Without a back rest, there isn't much movement you can do to change position. I could be misremembering though
Edit: of course you could just stand up every once in a while and that'd probably take care of it I guess, I'm not an Orthopedist