I wanted to call attention to an issue I experienced today so someone else might catch it earlier than I did. My initial assumptions of wet filament and ignore the quality issues were way off.
I believe the trigger that I missed was what I thought was a bit of under and then over extrusion on Toolhead 1 with PLA. When I switched to PETG the hotend came out further and really scrapped the bed.
About a week ago I noticed that the first layer when I used Toolhead 1 was very under extruded. I checked the nozzle and it was clean with no blobs on the end. I forgot about it and then this week when printing it was over extruding and put it on my list of things to figure out in the future. Today I switched from printing PLA to PETG and watched the first layer, not something I have done much recently with the U1. It started the print on Toolhead 2, starting fine, then switched to Toolhead 1 and the prime tower was significantly over extruded. Before I could click the pause print icon, it started to scrape into the build plate and I stopped the print. After docking Toolhead 1 it reported an error that it was not docked successfully and to inspect. Visually inspecting the nozzle was not able to sit on the silicone dribble plug and I took the toolhead off for a better inspection. After some tinkering I determined the nozzle was 3mm further from the heatsink than the spare provided in the box. I decided to swap in the 0.4mm Hardened nozzle since it was ready with the heater and thermistor attached.
https://wiki.snapmaker.com/en/snapmaker_u1/troubleshooting/nozzle_scraping_the_build_plate#step2
This is when I went on the Wiki to check the nozzle swap directions from included sheet with the 0.4mm Hardened Hotend. While typing in the search it popped up with the nozzle scraping and my issue and pictures were almost exactly as described in Cause 4. After swapping the nozzle according to the instructions, I ran the toolhead offset calibration in case anything was off and everything seems to be working now.
The first layer is back to perfect and I know what to look for with the other toolheads if anything starts acting weird. I may still open a ticket so the issue can be tracked on their side, but other than this it has been printing perfectly for more than 2 months.