Just let them do the job you are paying them for.
I've had great confidence in this builder for everything except for this. I think they build good tight homes and have heard good recommendations from friends and others in town... but I am clearly an outlier when it comes to the EV option they have.
The sales agent initially send me a picture of a NEMA 14-50 saying that was their EV Pre Wire... which I was very surprised required a service upgrade past 200A.
A building manager that I talked to when finalizing the plans and any additions that I made said it would be a 100A circuit just capped off.
The onsite construction manager when I did my electric pre-job walk through confirmed the same 100A to a capped box... but when I asked if it would include 2 hot, 1 neutral, and a ground, he was uncertain and said he would have to ask his electric sub when he did the walk through with that person, I think this coming Thursday. He also wasn't sure exactly what it would be when it came to wire size etc.
So... I think the only straight answer I'll get from them about exactly what this is, is from the electrician the problem is, owners usually aren't included in on that meeting, since we go around with the onsite construction manager a few days before and the low voltage guy. It's at that walk through they explain where switches will be and any additional outlets I've added etc. Then that gets communicated to the people actually doing the work.
Again, I'm hoping I can get included in on the electric sub's walk through so I can ask some questions and answer some. I suspect they would be able to clear everything up for me within minutes and get an idea for exactly what I'm looking to do. (Heck, this person might not have seen an EVSE installed if they just have been working with this builder for the last few years in my area so they might know not even know exactly how the end use is wired up/mounted).
That's a good point about asking if I can get in before the drywall is put up. I'll reach out to the sales agent and ask for that. These guys move quick, so I'm hoping they're not coming in right behind the electric work and dry walling the same day or something. I don't want to slow down any work since I'm already predicted to get close to when my rate lock expires and I'm locked a full percentage point or more under what today's rates are. I've got like 15 days wiggle room but that seems scary to me, if I cause them to get behind a week or something because they move to one of the next five homes that are JUST a little behind mine and THEN circle back to drywall mine... I'll be really stressed.