Do you have to dissolve nose filler now and again? Or can you continue to top it up without it spreading?

The nose filler I have in my bridge mainly doesn’t fully dissolve for a long long time. It gets to a point where it’s too low for my liking but there is still a bit of filler there. Is it possible to keep topping it up at this point I.e. when it gets to a point that I think is too low? Without it looking bad and spreading laterally in the long run? Or should I be dissolving every few sessions…. I am trying to stay away from using dissolver at all costs.