I have a feeling this is going to confuse some, but... Full compression is full compression, regardless of lift or not. The difference is, with a lift when you're on a hard trail you might only fully compress and rub once or twice all day long. With no lift, you're closer to full compression at rest so a small bump in the road may fully compress the suspension. In other words, with a 3" sus lift, your struts are always 3" farther away from full compression so it takes a bigger obstacle to push it all the way up there and make it rub, but where the tire and strut top out at is still the same spot - lift or no lift.

Even with a 3" sus lift and fender trimming, 285s are still going to rub at full compression especially when the steering is turned to one side (full lock). That's why you see so many of us (myself included) running small body lifts on top of our sus lifts. BLs are the only real way (short of tubbing your fenders) to get rid of the rubbing at full compression.

I think you'll be fine if you do the same amount of trimming we have all done and just take it easy on the speed bumps until you get the lift.