I have no answer to your question, but when I need a couple of screws with an odd length I cut them with a cheap and crappy wire cut/crimp/strip tool, like the one in the picture.
If you look at the section where the rivet is, you can see a couple of holes with markings "M4", "M3" and so on.
They are for cutting screws.
Works mostly ok, never perfect but usually good enough.
I imagine a tool like this can be found in almost any hardware shop, for maybe 5 or 10 dollars.
You may in fact already have one.
If you're like me then you just have to open up some of all those cheap, handy and crappy tool sets you have accumulated over the years.
You know, all those nice-to-have-in-the-car tool sets.
I did, and found several crimpers.