Not really. Why then does David Tubb make a carrier weight system? Or why would the SCAR17's recoil be so mild with its massive reciprocating mass? Why would PWS make an enhanced DI AR15 carrier that's nearly equivalent to a standard M16 with CWS installed? Because it increases felt recoil? I simply, but respectfully, disagree that using the lightest buffer available is best in all cases or that it correlates to softer/less/smoother recoil regardless of caliber or the rifle's specific characteristics.
I see the benefit of lightweight carrier and buffer combos along with an adj GB being geared towards speeding up cyclic rate (albeit doing so with the least amount of recoil possible) for fast follow up shots in your 3 gun set ups rather than smoothing out the recoil impulse. I'm not saying to use the heaviest buffer available, but I wouldn't consider using a 6.5oz buffer - that's only an ounce heavier than a standard Armalite carbine buffer - a real big deal. IMO, It'll actually give you more margin of error with respect to how smooth it will shoot with different loads and switching back and forth from suppressed to non etc.
I prefer my bolt stay locked in chamber as long as possible for a few reasons. Brass is in FAR better shape, and gas is utilized pushing the projectile. A heavy buffer (or heavier than std weight for whatever platform & caliber) will noticeably increase lock time. How heavy you go would depend on gas port location, size, and how much barrel length you have forward of the port. Those aspects, along with your carrier weight and it's length of travel will ultimately dictate how heavy your buffer needs to be. If you're running a std 7" buffer tube it's difficult to not only decrease the velocity your carrier is moving rearward, but more so to time the cycling of the gun appropriately and ensure the gun itself it absorbing as much of the energy transfer from the recoil as possible. A heavy buffer certainly helps absorb more of that energy than would a lighter buffer - and becomes a huge plus when shooting suppressed.
Just because you're using more gas to push more weight doesn't mean there's anymore recoil. Redirecting gas is important, but the adj GB isn't a black hole where gas just disappears. It's going somewhere. If you're using more gas to push a heavier reciprocating mass you would then have less exiting the muzzle implying you'd have a reduction in muzzle blast and, hence, less muzzle rise.
The point should be to use any and every tool at your disposal to use the gas created from 'X' grains of powder pushing 'Y' bullet at 'Z' velocity in the most efficient way possible while BALANCING where and how much gas you need to use for various operating mechanisms to function as close to perfect as possible.
The process of balancing gas dispersion in a consistent, repeatable fashion can vary dramatically depending on powders being used (volume, burn rate, etc), application specific variables (hunting vs comps - bullets being used, minimum velocity thresholds related to terminal performance, etc), suppressed/non-suppressed, along with an individual's preferences related to how he/she prefers a rifle to shoot that might change how one distributes gas to effectively manage things like recoil impulse, cyclic rate, and reliability across that spectrum of ever changing variables. A heavy(ier) buffer - in conjunction with an adj GB - have always been crucial to getting my rigs right where I want them.