Most people don’t have one. We didn’t. We sent in photos etc. Because of our limited wall space in the garage on the wall opposite the main service panel and with other equipment on it, plus the fact I wanted the gateway and inverter on the opposite garage wall with the PowerWalls, I think it would have been better in our case to have had someone come out. Electrician and his team had more to do than I think they thought and so were kind of at a disadvantage. I think for most homes though it’s pretty straight forward and not usually a necessity.
If they see for a solar install looking at aerial photos there might be an issue (vents, tiles, age of house/roof, older neighborhood, softscaping potential issues), they might suggest one. I think it depends on the crews also available to do them. Of course the wildcard can sometimes be the city issuing the permit and checking your house plans along with the permit ones or even the utility can raise concerns. A site visit doesn’t necessarily help if those come up. It does help if they've worked with the city before.
There are still many homeowners who might not be tech savvy to take photos on their cellphone and send. Stuff like that. Otherwise the install crews can be fairly adaptable, more so with the non-roof part.