Yes, it should be quite safe in that velocity range with a 225 grain or lighter bullet. I think those CAS loads are sub 800 fps, though, not sure the weight of the bullet.
I push a standard load of 255 grain flat point to about 950 fps with a charge of 8.3 grains of Unique in my Blackhawk. I would NOT fire that round in a Remington. It would be safe in an 1973 Colt/clone. So, you see, lighter the better in the Remmy.
These guns are great fun with cartridge conversions and a lot easier to clean up. My 200 grain .45ACP load shoots to the exact POA as my cap and ball rounds using RB and 30 grains of Pyrodex P with cornmeal filler. It's also just as accurate. And, the gun just LOOKS so good.
It hangs from my bed post in a buscadero rig with the .45ACP conversion in it. I have no doubt it'd take care of business with the cap and ball, let alone .45ACP. It's right there in easy reach and will get me to my shotgun if need arises and it looks so cool hanging from that headboard with the big Texas star in the middle.
I'm retired, no kids, and it's something of a home decor thing with me. LOL! I could hang my Ruger there, but the Remmy is so authentic and cheaper to replace if someone busted in here on the rare occasion I'm out of the house. That ain't likely, though, since I live WELL off the highway in the middle of nowhere down a rough 2 mile long dirt road at the very end. The few neighbors I have are armed and know all the trucks that belong down here.