The 135g was highly destructive at 2k fps. Complete fragmentation. At 1800 maybe you get a longer neck length (as long as they upset consistently). Too small of a sample size to say for sure, but I certainly wouldn't hesitate at or a bit below 2k.
I preferred everything about the 3-12 LRHS except the reticle and 50 spline turret. But the reticle improvement is dramatic and for big game hunting gives the edge to the rs1.2 for me. The 3-12 LRHS with an improved reticle and a few OZ lighter is the ideal scope.
My primary hunting rifle remains in a Bravo since the Rokstok I ordered 15 months ago still hasn't arrived. I rebarreled to a 4" longer (20 -> 24), 1 pound heavier barrel before a recent hunt and it balances a lot better than before. I'd think a thinner barrel with suppressor would balance fine...
You can still aim/hit small on animals. Practice bracketing on larger targets or animal targets at distance. Preferably targets with feedback. Obviously wind becomes a thing.
Elk from a very recent hunt. 2 shots an inch apart at 405 yards.
On real animals, a thorough understanding of...
I've been shooting that exact comparison side by side the past few days. 6.5cm/130 and 6cm/109. Same weight rifles, same stock. The recoil difference is fairly substantial. It "feels" like more than 2ft lbs to me. Putting a brake on the 6.5 reduces reticle movement to just less than bare muzzle...