I have in the past.. some UGORG strains and a couple of rare ones but planting 10+ and repotting, feeding them for 5 weeks to then throw 6 away isn't feasible. I would do Regs if I had the facilities to take and nurture the cuttings.
I run a single 400w HPS and I use a 450m3/h RVK150A1 systemair Fan.
I use this on an SMS Fam speed controller.
This allows me to set my temp at 24C and the controller speeds up or slows down the fan to keep the desired temp.
I Intake Cold air from my soffits Of my attic space and dump my hot air into my attic which is well ventilated. (Obviously carbon filtered)
This allows my fan to run almost at 10% during cold days to keep the room at 24C and flat out during the summer to maintain 24C.
I too run my lights at night.
When I utilised a 600w pre 2012 I used an air cooled reflector and a sealed lighting rig (meaning no grow room air passed through it) utilising a RVK150L1 fan and a secondary 5” RVK125A1 for exchange and filtering.