Ensure you have the necessary tools: You will need a good pair of wire cutters or flush cutters, fine-grit sandpaper or a file, and possibly a soldering iron (if the pins are soldered to the PCB).

Examine the PCB: Carefully inspect the pins to determine if they are soldered to the PCB. If they are soldered, desoldering the pins may be necessary before shortening them.

Measure and mark: Determine the desired length you want the pins to be and mark it on each pin individually. Double-check your measurements to ensure accuracy.

Cut the pins: Use the wire cutters or flush cutters to trim the pins to the desired length. Cut them one at a time to maintain precision.

Smooth the edges: After cutting, use fine-grit sandpaper or a file to smooth any rough edges or burrs left from the cutting process. This step is crucial to prevent any damage to the PCB or other components.

Test and reassemble: Once the pins are trimmed and smoothed, test the keyboard to ensure proper functionality before reassembling it. Make sure the modified pins do not interfere with any other components or cause any connectivity issues.

one option you might consider is the Keyboardio Model 01. It is a fully split, columnar staggered keyboard with an ortholinear layout. It falls within the 60% to 85% size range, has no thumb cluster, and is available in a US ANSI layout. While it doesn't precisely match all your specifications, it may come close to what you're looking for.

JEEEEZ.That colours of buttons. Wanna do smth with mine too

Thanks a lot for your help, Hasu.
I tried the firmware from your last post and it works 
There are two keys that don't work: "Fn" and the second "\" located next to "Z" (for some reason this keyboard has two "\" keys)

I would definitely try to create F23 and F22 versions (with and without modifiers). Not sure if I'm capable of doing that Taran's tutorial looked like a foreign language to me.
Anyway, thanks again. I will email you to order more converters.

P.S.
If someone is looking for a compact wireless marco keyboard at an affordable price, I highly recommend Rapoo 9300M. Build quality is great and you can buy it for $20 USD.

So Mike & Patrick took revenue as profits, didn't pay their invoices to all manufacturers and on top of that didn't even pay you designers your cut?

Pretty much. Not only that, but they are sitting on paid inventory with no motive to ship. They basically got caught red-handed and are more than willing to let it all burn to the ground.

It's not just GMK sets, but MW, artisan, deskmats and keyboard GBs too.