Most parts take only 15 layers on my FDM printer. So printing of one set doesn't take long, but I want more parts to be printed in one session. Ideally hundreds of parts at once.

Parts are flat.  What if I stack them layer by layer with a thin gap?

Here is the stl: 1x1-32.stl

A gap of 0.3 mm makes one loose layer.

Here it's printed:

And cut with utility knife:

New parts work good. They are like the previous flat printed parts except for underside which has very rough surface due bridging.

I tried them in practical usage.

It works. If needed, I can make about 500 flat parts in one print.