when I play HU I ask the guy b4 we start if we wanna run it twice or not and we both agree to stick to it for the whole match.
I think it's a good idea in general, personally never have it on - let it riddddddddddddde

if you think it's a good idea to not do it then why do you ask? surely better to just say you're not doing it at the start
No I think it IS A GOOD idea in general, I choose not to have it on in 6max games cos it's just easier and I dont mind taking the variance on. in HU games I just ask at the start, if the other guy wants to then I put it on it makes abso no difference to me, id say 75%+ of the time we both say we dont want to do it, but having said never once not done it when 3+ tabling the same person HU