How to print Nylon (Co-PA) ?  

RE:

1- Are you sure that your custom enclosure protects well the top of the printer from draughts and sudden temp. changes ?.  35C seems a bit low for printing nylon reliably. I have no experience with this brand of filament but, if you could get 45C or more inside the  enclosure, I bet that your  results would improve.

2- Nylon doesn’t like PEI beds. It’s very difficult to get the strong adhesion required to avoid warping, specially on large models. Using adhesive on the bed helps, but only up to a point. The real solution for these filaments is a Prusa PA powder coated steel sheet, although the model for the XL is very expensive and maybe not worth the investment, if you aren’t gonna print nylon filaments on a regular basis.

RE: How to print Nylon (Co-PA) ?

(1) The reason for a lower temp is my levers are still original petg, can get higher temp by closing holes in future.

(2) I only have pei and textured powder coated plates, will try to use the textured also.

In between I have used kores glue stick instead of 3dlac, looks the adhesion is far better, just still not ideal for printing larger parts.

RE: How to print Nylon (Co-PA) ?

Don't expect that the textured plate will be better than the smooth in this regard, rather on the contrary.

Enabling a large brim on the Slicer settings helps a bit. So it does adding flat discs at the corners of square models ( 'Mickey Mouse ears' ).

Personally, I don't like glue stick. Too messy and gives a rough look to the bottom surface. I prefer 3dLac for a general purpose adhesive, although for nylon filaments doesn't does much. An alternative product is Dimafix. I use it for printing PC on the smooth plate. It's quite expensive but works very well at high bed temperatures  (90C and above).

Nevertheless, if you try a PA powder coated plate, you won't look elsewhere.