hmm if the orbital survey does not pick up all minerals, it gets very complicated to pick potential mining colonies.
the ground survey is not realy fast atm - ok there is a change comming, but who knows, how it will be?
but if you would need to ground survey each planet/moon for specivic mineral values, you would be surveying with 0% survey ppl, because you just run out of usefull ones.(actualy for me only the 30% survey guys are actualy usefull) in additon i think about the game flow a little, and you would realy spend alot of time sending out survey teams to each planet, and make all of thouse colonies that you can actualy ground survey them.
i think it would be enough, to have the need to ground survey mineral rich planets, like setting all access values low without ground survey.
if the ground survey can be speedup with research, it could make sence to slow it down again, a little maybe with the planetary suitability value. but it gets complicated with asteroids? or just use a set value there?