80mm is a rather standard stem length. Certainly not unusual enough to wish to chop up a frame.

You can buy rather short stems if you need.

https://www.ebay.com/itm/Vintage-Sak...2/253980558513



With all the modern CNC work, you should be able to find someone to pantograph it. Etching?

But, you may find yourself a little short on real estate for your pantograph.

I think some drop bars also have a little less reach than others. Although, you may find yourself with compact bars and hunting for a 31.8mm stem.

https://www.ebay.com/itm/J-L-NOS-Thr...s/351784121927

https://www.ebay.com/itm/J-L-NOS-Thr...s/223209107505

Again, customize with the panto you wish. Perhaps if you buy 100, the Chinese company will customize to your needs.