you can also try and beat your verification
1) send in all your transcripts in May, including the one that isn't completed yet (assuming it has some grades on it, which may be necessary)
2) list current classes as "ongoing" on AMCAS
3) submit early, but not day 1
4) as soon as your transcript is available, rush send it to AMCAS.
This only works if you have grades on that transcript already. Basically, AMCAS has an automated check to see if they received a transcript from every school you claimed to have attended. If they do, they put you in queue for verification. If they don't, they wait until they receive one. They don't actually look at the transcript until verification time. I'm not sure what happens if they realize then that the transcript is incomplete (could range from putting you in the back of the queue, to putting you on the side, to simply verifying you as is without those additional grades). I'm also not sure what they would do if they suddenly got a transcript they weren't expecting (because courses were listed as ongoing) and whether that would update your place in the queue.. who knows.
If the timing is right, AMCAS will put you in the verification queue but will receive your updated transcript before they start verifying your application. This will NOT impact your place on the queue but they WILL use your most recent transcript from each school for verification and thus, WILL put in those grades for you (others claim they don't.. they did for me.. you could also just list grades here and they will correct them for you if you're wrong). It's somewhat of a risk but could get you the best of both worlds in terms of more grades and an earlier application.. I just wouldn't apply day 1 because you're going to need some amount of time to get your transcript there depending on when its available it.
I did this exact thing last summer and it worked.. I beat my verification by two days. Got kinda lucky considering how backed up AMCAS was so depending on when your transcript would be available, you may want to wait until week 2 where you'll still be verified in early July at worst.