Definitely keep pumping OD and start pumping passing and 1v1. His only shot is as a PG and even that is tough with the deficiency of JR as it is the slowest guard skill to train. He is a very nice prospect though. I would think a build like 11/8/16/14/12/13 for guard skills would put him in consideration.
That would mean you would need 5 pops in JS and JR. 6 OD pops, 6 passing, 4 driving, and 2 handling pops.
I find it highly unlikely to get all of that training in. You have 28 weeks until his 21 yo season and 28 pops. I think it will take roughly 32 weeks or so to get those numbers. However with a good trainer and some luck you could make it. Maybe at the start of the 21 season you shoot for a more realistic 10/7/15/14/12/12. I kept driving/handling the same as those will train quickly. This would be 24 pops which is much more feasible, but still highly unlikely IMO due to the training of very tough skills like OD/JR/JS. Obviously those are not exact numbers, but the JS/JR deficiency really makes it tough unless the U21 manager at the time uses him as a LI PG only.
That's just my two cents. I feel I was very generous on training speed too so who knows if even the second set of numbers can happen. 4 JS = 8 weeks usually. 4 JR = 6-7 weeks due to cross training and elastic effect (may be generous still). 5 OD = 9-10 weeks...no way really around that. could be more really. 5 passing = 8 weeks...again generous maybe but cross training with 1v1 for forwards helps. 4DR/2HA = 5 weeks ...HA could pop a third time to up it to 15 during the same trainings. I'm also assuming IS will pop once through cross training which at least gets it off of atrocious. Even the low numbers on the training weeks equals out to 36 weeks. So this training plan will go through the majority of the 21st season if not all of it. Maybe by the end of the season he will be useful which is better than nothing.
I dunno if this helps but this is my ramble and analysis. Tell me I'm an idiot if you want, just throwing some stuff out there.