According to the manufacturer these Ameriglo Tritium Front Rear Tall Suppressor Sights will not work on 42/43 variants. Based on that information they will not work on a Glock 43x.
Yes, they fit my Glock 43x. The “full sized” rear sight is just a hair less that the width of the 43x slide. The width only concern I have is if the relation of the heights of the front and rear are different for subcompact models. I have not sighted the gun in yet and can’t say. The front sight height of the XL is .315”, the same as the suppressor sight marketed for a 43x. The .315” height is a true co-witness with the top of the front sight in the middle of a Vortex Defender which mounts direct without an adapter plate. I am ordering a couple adapter plates to raise the red dot to have a the front sight in the lower 1/4 of the window.
Front sight hole is the same on all glocks and will easily fit. The rear sight will slide into the dovetail on your 43x. The issue is that the 43x is narrower than standard glocks so the rear sight may protrude from the sides of your slide.