I like the Lee molds for my 50-70 but there is not enough mass and they heat up real fast. I wish NOE made the same profile.
My solution is to run my NOE 311284 followed by the Lee 515-500 followed by the Lee 515-450 in sequence. It has been a fun Monday night. Temps stayed abut right with all the molds.
My lead Pot does not have a temp control other than high and low. I run it on low.