A couple of thoughts - but yes, you can find recipes for faster loads up to at least 1400 fps / mostly using 1 oz of shot.
Recoil is cumulative / and tiring - regardless of how big you are ( I'm 6'5" and 280 lbs ) but it will wear anyone down over a 4 day event where you might easily shoot 1,000 shells or 40 boxes.... and do the math / on a target 40 yards away or 120 feet / how much faster does a shot pattern traveling 1400 fps reach the target / vs 1200 fps .... Remember the idea of a shotgun is to put a 30" pattern, on the target, at the kill range - so you change your choke accordingly. If you miss the center of the pattern a couple inches left / or a couple inches right ... it doesn't matter. In fact worrying about it - may cause you to lose focus on what's really important - feeling the lead, pulling the trigger and follow thru...
Staying sharp on birds ....is more about confidence and fundamentals - of smooth swing, feel the lead and follow thru than the shell you shoot.
For any of the clay target games - you cannot shoot a shell with shot size over 7 1/2's ....and while most won't limit your velocity - anything over 1300 fps ( like a Remington Nitro, 1 1/8 oz of shot ) is way too much in my opinion. The last I knew, many of the better shooters in the country shoot 1 oz loads / from 1200 - 1225 fps ....and they shoot a lot of shells of 1oz of 8's ...and while there are always exceptions / faster may cause more holes in the pattern, etc if you read about reloading, shot patterns, etc.
I would recommend you reload 1 oz of shot / around 1200 fps ...and you'll be plenty sharp when duck season rolls around. Shoot some sporting clays, some Skeet and some Trap ....and work on keeping your shoulders level, solid gun mount, good follow thru ( good mechanics ) vs hotter shells / you'll save some money and be a better wing shooter down the road.