It generally takes 1 day per 1000 images being processed but if you have used too much overlap or didn't follow the Data Collection guidelines it can be longer than that. It started about 29 hours ago at this point so it is still within normal ranges. There was a small delay while other work had priority (ASAP urgency level) but that didn't affect things too much.
I just noticed that it was with the P1 which has over double the resolution of other cameras so it may take longer to process that imagery anyway.
I bet it will be done by morning or even later this evening since it is in the final stages of that first part which takes most of the time.
There does appear to be an issue with the ETA calculation and we will give that a look.