GMK caps do not work on R3 switches where the led faces north (upside down switch placement). Well, they work, but have a muted bottoming out since the keycap collides with the switch housing. Yes, this is a thing. Yes I believe thousands of GMK users have overlooked it.
LEDS are in the South position.
Also, you want 1.8mm LEDS.
Will 2x3x4 LEDs still work for DSA or SA but not GMK?
Yes this absolutely is a thing. Many people are nescient and no one seems to ever talk about it. So many people putting gmk or similar low profile sets on upside down switches.
Gladly it seems that all, if not most quality pcbs for custom builds are designed for correct switch orientation.
Also with LEDs. Even with south positioned LEDs for me personally GMK caps still bottom out on the LED.
I've tried 2x3x4, even 1.8 LEDs I got from Winkeyless still bottom out on the keycap. The only thing that works for me is clear switchtops with 2x3x4 leds mounted underneath the switchtop.
However I think this may not work with holtite sockets.
Ok but I need to know if 2x3x4 will work for SA and DSA caps on this PCB or else I need to buy some 1.8s since I've already bought the 2x3x4s.
I obviously don't have this PCB, but I don't see why it would differ from any other. I have placed 2x3x4 leds in similar boards without issue. I remember a few that I had to rework because they weren't pushed all the way in before I soldered them, but as long as they are flush there should be no issue with DSA or SA keycaps.
However, since you have time before the board arrives, you might as well get some 1.8mm LEDs. They loolk nice, seem to be slightly brighter, and will be better compatible if you decide to put cherry profile caps on it down the road.
You can get them from eBay for cheap or even zeal has some for a decent price, if you want them quicker.
