Well, when it comes to PETG - even the Profiles on my new adventure were a complete disaster too. If you are into PETG, absolutely no problem - just PLA drives me crazy…
Fist layer I always go down to 0.15, the PETG really need to pressed into the structure of the Plate. I even go down to a speed of 50mm/s by first layer infill by 105mm/s and than i do not go over 200mm/s at all and I run all PETG of every supplier at the same settings - no problems so far but maybe just more luck than understanding. The temperature of the nozzle I always put at the maximum - layer adhesion is much more important to me than beauty.
The first layer is the all-important one. Dirt on the nozzle that then solidifies is the end. That’s why I might put the lidar with the first layer inspection above all else and it’s so important to me.
Attention: Insufficient Z-hopping causes the layers to fall off… Z-Hoping is ones in the Filament Settings as well as there is a overwriting min. Z-Hope setting in the Printer settings (thanks to the person how found this overwriting setting out but I can`t find the trade anymore).
If nothing helps anymore on the first layer - there is also the old sugar trick. Although I have a little in an atomizer bottle and you have to spray it very carefully because otherwise everything sticks. To clean of the parts afterword also sucks a littel. For me, this is only an emergency trick, for example if the new PEI structured plates are not arrived… By the way, today I threw away 4 glue sticks - when will they stop putting unusable items to the printers, even a Knipex electronic side cutters cost 20 Euros (useful for lifetime and one that works) and all the stuff added scrap to the printer just ends up on the trash 
