To me, it sounds like he doesn't have a choice and has to go. Since he usually holds it when he knows he can't go, it would seem that he can't help it.
If I understand correctly, he goes potty in the morning, you feed him and put him in his crate. And then he has gone potty in the crate by the time you get home?
I think 8 hours is a bit much to hold it during the day. There is a difference between holding it while he is asleep and holding it during his 'active' hours. We, as humans, go a lot more during the day than we do at night
I also think that your pup will determine his own feeding schedule to a point. After 10 months, Cash decided that he wants a tiny bit of breakfast, but most of his daily food for dinner. I just adapted his feeding schedule and we haven't had problems since.
You can safely feed him once a day with some healthy treats in the morning to get him going. At 10 months, the risk of hypoglaecemia is almost non-existent, so no worries there. Just check that he isn't losing weight and is still full of energy.
I think the best solution to your problem would be to get someone to come over and take him out during the day. If you work nearby, take him for a walk during your lunch hour or get someone else to do it. He doesn't want to soil his crate, so simply give him an opportunity during the day to do his business outside.