After a few hickups I finished building my MK4 kit and Tukkari enclosure. The first few prints have been fantastic.
My MK4 kit had a couple bad bearings, so I replaced all the bearings and rods on the X and Y axes with MISUMI equivalents. I noticed that they have a fair bit less slop in the movement and are overall quieter.
I also made a custom G10+steel print sheet, and it's working exceptionally well with PETG. It sticks strongly while hot, and doesn't release until the bed drops below about 40 deg C at which point parts pop off easily. It leaves a super gloss surface on the first layer as well. If anyone is interested in building one, here are the parts I used:
(253.8x241mm steel sheet) https://www.aliexpress.us/item/2251832760691866.html
(white 250x240x1mm g10 sheet) https://www.aliexpress.us/item/2255801004367032.html
I bonded them together with 3M 200MP double-stick tape (which is thin, strong, and heat-resistant) and filed notches in the g10 to match the sheet. I didn't abrade the G10, PETG sticks perfectly while glossy. I was very careful about cleaning it with iso. alcohol before printing, and I wipe it again every print or two.
The filament dryer is a Sunlu S1 Plus, which has a built-in fan to circulate air for better drying. I printed this guide and used a PC4-M10 fitting and 4mm OD teflon tube with it to reduce friction into the enclosure:
https://www.thingiverse.com/thing:5234489
I'm quite happy with the setup. It is a little noisier in the enclosure than just on the table due to the melamine particle board panel vibrating while suspended on its plastic feet. I'll set it on foam and/or a paver eventually to improve this.
One thing to check on the factory models is the belt centering on the pulleys. Both my X and Y belts weren't centered correctly despite following the directions flawlessly, had to shim the motor mounts and also the printed Y motor holder where it mounts to the frame. Seems to be a common issue.
Hopefully the factory can find a good workaround for future revisions of the design. But gotta hand it to Prusa - they quickly respond when something needs be adjusted in the build. I remember the minor upgrades from the MK3s to the MK3s+ which seemed minor to some, but were huge for others (for me I see barely any difference in my farm, but hey I'm glad they made those changes if it increases the lifespan of the rails/bearings, etc).