I started a thread today about some bad habits I've picked up playing pool. I dont play snooker as much as I'd like, maybe once a week or twice if I'm lucky. Playing a mixture of the 2 shouldn't hinder either game in theory but from experience it does. The tables play completely different for a start and positional paths are different also. Firstly the pockets. The size isn't the issue but the cut of them is. Rounded jaws make balls rattle like no tomorrow and its hard to get back into the swing of what the pocket will accept when you have been playing pool a lot. The same can be said in reverse. If you play snooker a lot you have no idea what a pool pocket will accept and what cheating the pocket can achieve.
Secondly is the balls and cues used. Weight difference in balls and cue tip sizes make a difference to me. Going back to a larger tip in pool throws me off to start with but I soon get the swing of things. But my positional play sufferes hugely in pool coming up short a lot if I play snooker a lot.
Lastly is the styles of play. Completely different. Snooker is all out attack just trying to get a frame winning break, and safety battles are just about getting distance and the correct line on the CB. Leaving a shot is ok in snooker safety, just don't leave a shot to nothing. Pool is different and especially 8 ball. Safety play needs to be well thought out, and simply leaving distance isn't good enough against most.
If you play both in equal amounts then you can reap the benefit of both, but from my experience you don't play both equally. One usually gets more attention and the other suffers. But its like riding a bike, you never forget so it may seem one is suffering at first but it soon comes back to you.