I have shot as little as three days after a bedding job with no ill effects. While it's curing, I always store the rifle in a closet that's next to my water heater so it's pretty warm in there 24/7.
I have not bedded an aluminum block but I have quite a bit of experience with epoxies and metals. A thin skin of bedding material on the aluminum might flake or chip. If I were going to try it, I'd take some sandpaper and sand the aluminum down to bare metal getting rid of the aluminum oxide or the clear coat that prevents the oxide. Then, I'd take my dremel and carefully cut some shallow grooves into the area where the material will be. This would make some "key-slots" for lack of a better term for the material to grip into.
None of that may be necessay, and it may work just fine without these steps, but that's what I'd do.
JimF
