I have used 3 and 4 vane configs with the heats. Have ended up with the 4 vane with some offset for past 4 seasons with excellent results, I have no reason to change other than I like messing with stuff. Quiet. durable, provides nice clearance. Lots to love. No trouble shooting multiple mechanicals and vented fixed out to triple digit yardages. Solid 2 blades they also work. Although, if that was my go to head I would likely use a different config.
3 fletch was only OK imo. It works for mechanical and some fixed heads but was to finicky for my preference. Setups had to be perfect or they got wobbly.
I shoot a similar bow setup to you 80sih pounds and 28.5 DL. I generally setup up arrow weights to hit the 285 to 295 window.
As far as arrows go I can get away with 300 and bounce between them and 250. I cut short as possible and don't over load the front. Have shot the 5.0 with good results and the FMJ max. The FMJ build in 300 spine comes in at a little closer to my target weight for speed without softening the spine so used them this past season and really liked them. If doing 250 spine I would look hard at two options the Axis LR 4mm you mentioned and the RIP TKO from victory. If doing the 4mm the Podium titanium inserts are a good upgrade.
