For those worried about excessive recoil, the speed of the load and size of the load are two other issues to factor in. If you are shooting a lighter load with 6,000 PSI and velocity is less then 1150 FPS and you are shooting 7/8 oz loads imo blaze away. Knowing your exact load might give some more insight.
PS. Think about how many 2 3/4" oz loads have been shot in this gun in its life unless it was a safe queen. Folks between 1960 and when RST starting making ammo just shot what they could find and back in those days they shot a lot. I believe (could be wrong) that RST has been making ammo for about 30 years.
Not to put too fine a point on it but pressure generated has very little impact on recoil and what it does is quite oblique.
You rightly point to weight of the ejecta and speed it's accelerated to as key factors. The other significant element, in terms of what we feel, is weight of the gun, which is a moderating influence.
Its been my observation that far more damage is done to older gun by shooting shells with too much recoil than too much pressure. Its just that when you exceed the pressure threshold, the results are a little more likely to send you to emergency.