In all my years, dont think I've ever heard of a cracked bridge coming out of place & killing the engine. Be my luck though to say ok run it & that crazy piece come out.
Theres a mod can be done for that cracked bridge, but, only if that intake area at the top of the bridges not been widened to much. Your already using the 85/86 piston to be at that bore size, so the mod will be an easy task.
That little ding on the sleeve, like mentioned, let it ride.
You can take the cylinder all the way up to a 70.00mm YZ piston if you want. Will just need the thinner 2.5mm spacer plate instead of the 3.0mm on it now.
Neil