I have 2 single shot 45-70's, H&R and Henry. Haven't hunted with a 45-70 in years and don't ever plan to use one in ml season. I hunt very little in rifle season. It seems like a lot of hunters take chancy shots because they can chamber another round in short order for another chancy shot. One of the main reasons to keep it "incapable of being loaded from the breech" is to reduce harvest numbers in the early part of the rut.
I have to make every effort to make my sml shot count. From weighing powder to sizing bullets to the nearest .0001" for proper fit to keeping my powder and primers dry to taking advantage of the best possible humane shot placement. That might be the only shot you get. I heard one of my long time hunting partners tell someone that "If you hear him shoot, there is a deer on the ground".
Smokeless muzzleloaders come in lots of different variations, the most common are single shot conversions. We limit them to around 40kpsi which translates to a 250gr bullet at 2400 to 2500 fps. Comparable to a 45-70. They can be loaded lighter in bullet weight chargeweight, or powder burn rate. They can easily imitate black powder sub speeds. On the high end, short of a 50bmg, there isn't a gun in the woods that can outshoot a purpose built sml.
As for those saying my sml's will be worthless in the future, you better get that shot off with your little single shot pea shooter cause if I get my tracking system locked in that deer will be DRT.
In the grand scheme of things, effective range makes little difference in the ml harvest as most kill shots are less than 100 yards. Reload time makes more difference.
That said, hunt with what ever makes you happy within the law. Just please make every shot count. After all, that's what muzzleloading and further more, primitive hunting is all about.
I need to get with wobblyshot or one of the other traditional ml hunters /shooters. I'd love to build one and hunt with it. I think that will be my 2024 goal.