The custom keycaps, that’s a dream. I’d love if there was a good method for that. I laser cut my board myself, too (but at a mkser space), and would love to make custom keycaps for it.
To speed up the process and perhaps get less errors, could you possibly do all of them at once?
Since you cut the plate, you have the drawing, so you could place the legends appropriately on that, then place keycaps on all switches and press play?
Maybe you could start with small dots on four corner keycaps in one go to calibrate/not risk bad prints on a full keycap set.