I'd be inclined to try and push up to the next node with RE16 and check your velocity again. I'm at 43.3 in my 22" Bergara HMR. Like most of my other experiences with Alliant powders, SD/ES shrink considerably the closer you get to max pressure. My load is pretty warm, I'd definitely work up to it in a different rifle, but once I got my firing pin bushed for running small rifle primers, I dont have any pressure signed to speak up, 2 firings in and still havent needed to trim my brass.
My RE16 loads yield 2791fps from my 22" barrel with an SD of 9.8 (15round sample size). I shot a 3 shot group at 850yds last weekend that I could cover with my palm. If I load to similar pressures I'm getting about 150fps slower running H4350, same bullet (143gr ELD-X) as you are using. Unless you cant get good consistency with the RE16, I wouldn't bother with H4350. For heavies out of shorter Creedmoor barrels it just doesn't give as much speed.