A: Whoa. That was definitely one for the Code Warrior. "The Augmented Statistic line of realm abilities add their score bonus when the character's base, unmodified score is checked, so it is totally separate from item stat caps or spell stat caps. However, there is a hard stat cap of 450 for most ability checks so even if you somehow got your Strength to 472 (which, for most race/class combinations isn't actually possible) the game server would ignore anything beyond 450.
"Also, there isn't a "soft cap" like the questioner referred to (unlike skill specializations, which do have a minor effect past 50 for most). If s/he was able to get his/her strength to 322, they would get the full benefit for those 22 points.
"There are exceptions to every rule (for example, as most archers know, there's no benefit to archery draw time for increasing quickness above 250), but in general, Augmented Statistic realm abilities are, if not "exciting", definitely one of the safest bets when purchasing, and they will almost never run into "caps"."