This would be a fun project to make actually, heh. I could incorporate it into my bot I already use...
I don't think afk would be terribly useful, however, it could totally be possible and easy to make a bot that reads when you are in a match, does random stuff, and then at the end of the match would leave, join new queue, load match, etc.
Could even have the bot do some of the smaller things to get you bloodpoints I guess... (struggle on hook, self heal too I guess?).
I might do this just for the lols as it would be a fun project to work on with my freetime.