Tank role is supposed to be high risk, they others (dps and heal) arent bad, but you are on tank follow so a switched on person looking for it may detect
Because being trapped in an instance with only 4 people significantly increases the chances that someone notices you have inhuman reaction and bot-like movements / behavior. Honestly the only thing I feel somewhat safe using dungeonbuddy for is healer; tanks are very risky due to the fact that they lead / pull; DPS are iffy to me because of how the bot approaches mobs and ability to keep up with the group.
it's perfectly fine to use, just that it's not something you should ever do afk, if you'll go afk - it get's extramarital unsafe, but if you will be around it's perfectly fine.