For starters, my usual problem with grouping is that I'll gain experience too fast.

So ideally I'd have a toggle to reduce my exp gain so I could group with people more.

Also, loads of exp means easy to have lots of characters, which brings its own problems. Your enemies can easily know where you hide or rank by being your ally. People can log off Vs those in their pk range and log on those who are not at risk, or who dominate their own pk range etc.

I think I could nevertheless support this if you could apply a reduction factor of 10 on demand.