Hello my friend @smerrett, I had exactly the same concern as you. In my case, it was with a clear resin. Unfortunately, it will be quite difficult for you to find a post from FormLabs related to this, and when you do find one, they will discourage you from mixing resins. Usually, the guidance is not to mix them because it “probably won’t work” or because “the chemical composition of the resins is not mixable.”
But as I mentioned, I had the same challenge as you with Clear V4.1 resin. I simply reprogrammed my tank (which was already full of Clear V4 resin) and started the print. I didn’t even check the parameters of each resin to see if they were as different as you smartly did. Depending on the geometry of the part you’re going to print (simple or with a higher risk of failure), the printing parameters won’t have that much impact, and after post-curing everything will be fine, but you can still change these parameters considering the version that needs more “energy” / time to cure.
Anyway, I’ll leave the link of my full post here. Good luck, partner!!
Mixing Clear V4 and V4.1 - Projects & Prints - Formlabs Community Forum