I don’t understand what’s so sacrosanct about the super majority having to be 60% ; theoretically, why couldn’t it be another fraction, say 5/9 or 56 votes to stop cloture (the majority required in a Supreme Court decision BTW)… Or for that matter, any other number that the Senate powers that be want to make it, if you want to keep such a tradition?
Just go to what the Constitution proscribes and be done with it!
The cloture rule in the Senate was set at 2/3rds in 1917, then reduced to 3/5ths in 1975. Of course there is nothing special about these fractions - they can be changed again by the majority at any time.
https://www.senate.gov/artandhistory/history/common/briefing/Filibuster_Cloture.htm