When using the High temp plate to print PLA, it is usually advised to leave the front door open or remove the top glass to keep the chamber cool enough to not make the filament inside the nozzle too soft. In my case i don't want to open the front door because i'm scared to bump into it and break it, and i cannot remove the top glass because i have my AMS placed on top.

These are sloped supports to slightly rise the top glass on my X1C, this enables closing the front door while printing PLA with a high temp plate without the risk of the chamber getting too hot and the extruder clogging.

I've used this for months and it works perfectly, i can safely print PLA with the front door closed, and even having the AMS on top of the glass at an angle is not a problem, it doesn't slide at all.