Standard MOSFET regulator slightly reduces heat dissipation, but still needs decent cooling. Most of them are still shunt-type regulators.
I think the old Shindengen FH012AA is this type
Next best step is a regulator that has temperature protection, switches off when too hot, and on when cooled down (you'll ride on battery only for some time).
E.g. Shindengen FH020AA (50Amps) (now also used by Yamaha, Ducati, etc)
Ultimate step is a series-type regulator, much lower heat dissipation. Also the way to go if you fry your stator
Some of them have lower power capabilities, and/or limited max RPM.
E.g. Shindengen SH775 (max 9000 RPM, 35Amps)
Top of the bill is Shindengen SH847 (max 14k RPM, 50Amps), but is expensive, and BIG
Good information to be found at https://www.roadstercycle.com/
, also has some nice conversion sets
Oh, a good R/R is not cheap, don't go for the china knock-offs!