I finally took my 2018 MBP in and they replaced the upper case (I guess keyboard, touchbar, and more?) to fix the keyboard issue.

The work took about 2 days (drop-off, return). But I ended up buying a keyboard cover for it because the risk of particulate putting me in this situation again - and the consequences of that occurring - are of greater cost than the annoyance of a plastic film over the keyboard.

I recommend you take it in and do the same.