I registered my MK III in 2017, no surprises - but I knew I needed defrosters and I'm glad I have them, I've driven the car in heavy fog when I needed the wipers to keep the outside of the windshield clear and the defroster to keep the inside clear.
I'm finishing a MK IV now and have added side marker lights, windshield washers and back up lights, as I heard the rules changed a little. I'm not anticipating any problems passing the out of province inspection.
The "registration experience" should be trouble free as long a you have a copy of your out of province inspection, your Alberta VIN number and your insurance certificate.
Enjoy the build
Cheers
Mike