They did, until one was hit by a Spitfire and they did drop a 250kg bomb, which is why I questioned your 3 ton bomb load for Ju488s. Aerodynamics, power generation and cooling at 48,000 ft was experimental. At these altitudes measurement in feet or meters is academic, you are in a different atmosphere at 48,000 ft over Egypt than you are over UK. BTW as you know but didn't say the JU 86 used Nitrous Oxide to get up to 42/44,000 ft, it wasn't a "service altitude"The Luftwaffe did use Ju 86R reconnaissance aircraft (which could still carry a 250kg bomb) on harassment raids over the UK in 1942 and no doubt was aware of the problems of bombing accuracy from those heights.