Great experience for K1 interview. Arrive on time for your appointment, there is no use arriving more than 15 minutes before your time as you wait outside based on your timeslot. Be aware there’s multiple applicants per time (ex. 20 for 8:00), so don’t be worried if you’re not in the building by your time so long as you arrive for it. About 15 minutes before the next timeslot someone will come outside to arrange the line. Majority of applicants were Russian, then Ukrainian, followed by only a few Belarusians and Poles.
Embassy said the passport would be ready at the MBE (Mail Boxes and Etc.) in Warsaw within 3-5 days. There’s a phone number for the MBE you can call to see if it’s arrived, but they’ll text the beneficiary when it comes in. Note that the MBE had a big sign inside that said they wouldn’t be able to do anything until you got a notification from them. Ours was already ready 2 days after the interview.