tl;dr
So big only the tip could fit
First builds often have their shortcomings and blind spots you don't account for due to inexperience. Don't beat yourself up too much over it. I do wonder why the switches weren't sitting flush.
For my first build, I had no idea that switches were supposed to -clip- into the plate and thus my plate was not level with the method I used to mount the switches, many of them not having been clipped in.
Sometimes, the best way to handle it is to put them all in the plate first, then make sure every single pin is straight as can be and aligned properly, then ease everything down onto the PCB. It sounds like it'd be bad news, but it's a good way to make sure everything is flush and straight and you aren't fretting over a plate that isn't catching the switches.
