yeah. taking precautions would be good. i just didn't because i spent 83 hours getting to 100% and swimming 40 miles and didn't want to delete that progress.. lol
so if you're able to take that precaution; or willing to; do so.
i don't know if it has to do with me not getting the glitch or not but i saved my speed playthrough on a completely new save slot, so maybe open up a save slot if one isn't or use an unused one for your speed playthrough. don't know if it's related to avoiding the glitch or not, but would still be a good precaution to take (considering you don't have to lose any data, at least no important data, to take it