Official comment
Anytime you process a map the images need to be uploaded. You cannot reuse images that have been uploaded previously since we don't keep them beyond the time we need them to process the map.
It looks like you are on the Base plan which gets you the first 2 gigapixels of processing for free. Your 345 20 megapixel images is 6.9 total gigapixels so you would have to have enough pay-as-you-go points to process 4.9 gigapixels which is 980 points.
You can't do a Full 3D model since the source gigapixels is over the limit of 5 gigapixels for that feature. It isn't designed to be used with anything more than a single structure so you small neighborhood area wouldn't work well with it anyway.
The good news is you probably don't actually want to be using the Full 3D. What you likely want is to generate the Full Resolution OBJ file that you can view in 3D. This option is available in Step 2 of the uploader.
