On startup, muffining has more to do with vacuum depth.
For now I ramp manually. By sealing the oven and turning off the pump at various depths, for semi-standard time periods.
I’m on the fence as far as achieving that with N2 backfill into the oven. IF it was automagic, I might be more interested. Taking the human factor out seems like a win. mostly.
Might get around to programming a controller to controll vac depth at/near the pump. Or looking to see if I can get something off the shelf.