I currently have 4” cans with standard A19 led bulbs (some philips hue). I just got a couple 4” led retrofit bulbs that have the trim ring built in; I’m probably going to change most of them to the retrofit led because they’re much cleaner looking then the standard A19 bulb with separate trim ring. I can post some pics if it would help. If I were in the build stage I would definitely be going with a clean recessed led and not the screw in bulb cans. I don’t know if that helps at all.