We cannot allow spelling bots unless:
A. The bot is registered B. The bot draws from an approved list
A word like /thier/ can safely be changed to "their", since it's almost always a misspelling. However, there are many misspellings which can't be automatically corrected.
I don't mind HUMANS whiling away their time doing a bit of spell-check work; I do it myself, when I want to relax.
But if a machine can do it, then it probably shouldn't be done as a logged-in contributor (robot or "bot"). Rather, let's have our zealous programming staff write a custom spell-check program.
Uncle Ed