To aovid the heap creep (extruder clog, hotend), Bambulab suggested to open the printer door when using PLA filament. I usually make the door wide open (90 degrees), but the window door shakes. X1C has a nice block structure near the door and we can build a cover above it.

I printed a small part to verify the idea. I used 0.1mm face offset, and the structure fit the edges well.

The next step is to model the glass door and design a holder and again add 0.1 mm face offset. Here is final design.

To install it, you can follow the steps shown in the Gif, insert the glass door holder first and then fit the rest part. The door holder works well in the X1C, I guess it mayalso work in P1S or P1P. Hope someone can help test and verify it.