Hi Don, your question has popped up in the Australian Houzz site. American cabinetry has a greater widespread use of wood and painted wood than Australia. I'm envious. I'm not sure you'll get very much useful info here.

contact the public relations liaison at the company and they should be able to advise the contact details for the designer or architect who can provide specific information and/or take close up photos in good daylight and ask a paint supplier or paint section at Bunnings or similar for advice

We had timber tri-folds (also facing north) in our previous home and whilst our landlord sanded and re-finished every couple of years, they didn't stay fresh for very long and it affected the integrity of the timber too (slight warping and 'furring'). I used some Haymes Exterior Solarshield recently and it was brilliant over very poor quality timber and I noticed it's guaranteed for 20 years?! It was acrylic and very easy to use, but has sealed the timber beautifully. It may be better option for the longer term if you're happy with the look of painted. It would look lovely and one less thing to worry about!

PET can be a replacement of two-pack, PET laminated MDF board/plywood can be high gloss, matt finished, look as nice as two-pack