Just a few notes:
That must be an old stock frame kit you used. They no longer color the front rail system black and they no longer come with the mill bit.
If you’re not drilling pin holes with a mill, drill holes from each side. Runout will screw the holes up bigtime.
It appeared you installed the slide lock backwards. The groove faces the rear. The slide can potentially shoot off the front of the gun during live fire recoil and it can cause battery issues if installed incorrectly. I know it functioned properly, but I would check and correct if necessary.
Looks like you didn’t get a proper locking block pin (the one above the trigger pin) or it was inserted somewhere else. The locking block pin is dumbbell shaped being slightly larger on the ends than in the center. Those outer ends are the same diameter as the pins that come in the frame kit, so it really shouldn’t cause an issue. Just something I noticed.
The trigger pin always goes in last. You will not have an issue with the slide stop lever spring if you assemble this way.
That’s about it off the top of my head. Glock recommends not oiling the recoil spring assembly, but I sometimes use a dry lube on aftermarket springs to eliminate squeaking. Your build came out very nice. I wish they all went as smoothly as yours…I wouldn’t be nearly as busy on reddit helping folks fix and troubleshoot their builds! To be fair though, there are a lot of people out there that are building the first firearm they’ve ever owned.