I have a 2018 X1 28i with standard halogen bulbs. I purchased the TechMax via Amazon based off of BulbFacts review
There was no coding issues, however I got the flickering issue at startup due to the car sending quick low voltage to check if the bulbs are out. I contacted the seller and they sent me a decoder for free which bypasses the start up check therefore fixed the flickering issue.
Install was quick and simple if you're somewhat decent with DIY maybe 2/10 difficulty... Accessing the bulbs was easy. Pop the hood, turn the large cover behind the headlights to have access, remove bulb harness, remove metal prong to release the bulbs (hardest part), remove old bulb, replace new bulb, replace metal prong, attach harness, close cover. All done.