The 45 ACP is 'spring regulated' to function with 230 gn bullets. Factory recoil springs are in the 16-18 lb recoil range, which is what the 1911A1 pistol fucntions best at.
You didn't say that you were loading the 185s 'hot' for personal defense, only that you preferred the lighter bullet because it keeps them working longer with less pounding - how much longer than 40-50,000 rounds do you want or need? Twice that?
Change your springs every 5,000 rounds and you will be fine.
I prefer the 230 gn slug in my 45s, at mil-spec velocities or better, and protect the longevity of my pistols with heavier recoil springs. My 40 y/o aluminum framed Colt Commander just got back from the gunshop after having a new plunger tube installed and I took it out to the range and shot the snot outta it just to make sure the repair was effective and that the gun still shot where I wanted it to. This piece has had more than 10k rounds through it, most mil-spec ball or heavier handloads and it is still kickin' up a storm, so I wouldn't worry too awfull much about wearing out your pistol.
You may need to go to a lighter weight recoil spring though if you prefer the lighter slugs. Although your pistol may function with lighter weight slugs it is possible that you may experience ejection problems with lower powered loads. JMTCW. Mikey.