PETG first layer / Lack v2 Enclosure printing  

PETG first layer / Lack v2 Enclosure printing

Using a stock Prusa i3 MK3S, maybe 300ish hours total time in use so far.

I have been trying to print the Prusa Lack v2 enclosure pieces ( https://www.prusaprinters.org/prints/3673-mmu2s-enclosure#_ga=2.43350757.1912471863.1590544392-497805159.1585537551), and have gotten through most of it except for the last few pieces which are fairly tall and thin. They are ~7 hour prints that I've tried three times now, with it failing around 5 hours in/right above 130mm tall.

Looking close, it appears the edges are curling up from the textured sheet bed, elevating it slightly and eventually causing the print head to knock the piece over. Looking back at some of the larger pieces, there was lots of curling on them too, but the piece was large enough to hold to the bed.

I have been doing my first layer at 255c nozzle temp, bed at 90c, with layers above at 250c, leaving bed at 90c. My last test, I tried the default profile for Prusament PETG (240c first layer) to see if maybe I was going too hot, and it barely adhered with a freshly cleaned plate (dish soap and warm water, wiped with paper towel, dried with paper towel, then wiped again with ISO 91%). This is with a 5mm brim, and skirt set to 4mm to try and help maintain structure.

First question is, given the images above, how do I need to look into tuning my heat settings?

Second question, what can I do to improve adhesion of PETG on the textured plate so that it doesn't curl (unsure if this is temp related. Prusa KB says not to use glue/etc on the textured plate).