How many is too many TMR copies.

My main question is, I've read further on that we will be able to combine some of these MTRs for better versions of that and I'd like a little more info on it

But how many TMR is too many in your opinion?

Should I merge all my Yshtolas into 3 100% or keep 6 at 50% and farm the rest of the way so later I can merge her 6x Shard of Genius into a better version x3?

Same with other stuff. 💖