A 300 grain jacketed bullet at 2700 fps causes me to wonder if your bullet performs well at close range. If you are using standard pistol grade bullets in sabots they were never intended for that velocity. You are setting yourself up for the catastrophic bullet failures of the early Weatherbys before bullet technology caught up with Weatherby velocities. Personally, this sort of thing doesn't interest me. I use fairly standard inlines for some hunting and am satisfied with 1350 to 1900 fps depending on the load and powder charge. I took a .50 caliber inline to South Africa and shot 120 grains of Pyrodex RS and a 375 grain soft lead bullet and enjoyed excellent performance out to 145 yards on several sizes of plains game. The other point is that even though you are meeting the letter of the law is you muzzleloader safe in the county you mention? High population concentrations make me nervous. I hunt one area of my state with a 12 gauge slug gun because of the proximity of houses and semi-rural farmsteads and while my effective range is only about 100 yards, I manage to take a deer every season I hunt up there.
The upshot of all this is whether you consider what you are doing as safe or really necessary. Do you really need a muzzleloader that generates 2700 fps velocities?