Once you max your skill you won't need to worry about it anymore, really. You won't fail picking so you can just wait for the guard to pass and sneak in, get what you want, and wander out, no worry about sime consuming failed attempts (and i say time consuming only because sometimes it takes a long bit of spam to get a success on not trivial doors). As it stands, I haven't found a locked door that is pickable by 255 skill, that I can't get open because of guards. Sure, I mess up every now and then, but thats sloppyness and aslo my own fault. When i get too much heat i just sit myself in the rogue guild or something and hop on a mining bot for a bit.