u/ClassicalCockatrice

Hi everyone, I found this snail on the footpath with a broken shell and have been keeping it in snail hospital (snospital) until it heals.
But I have read some snail care sources that say you should ‘remove’ any sharp or loose parts of the shell.
There’s a big hole between the shell entrance and the main body (pics attached). I was wondering if I should remove the remaining lip shell or keep it? It doesn’t seem to be impeding movement and I was going to leave it, but I’m a little worried about it growing back ‘funny’. I’m interested to see what my fellow snail physicians think. Thanks!