[1.1.50] Factorio does not detect ZMK hold-tap modifiers

[raiguard]

A bit of a niche issue here. I am using a custom mechanical keyboard running the ZMK keyboard firmware, which, among other things, allows remapping and multiple layers. The feature I am using is called hold-tap, which makes a key behave as one key when held, or another when pressed. In my case, I have capslock set to be control when held, and escape when pressed.

If I hold capslock (control) and press another key within 200 ms, it will send both control and the other key (i.e. ctrl+e). If I wait for 200 ms, it will send control as held, so when I press another key it will behave just like a normal keyboard. In the first instance, every single program on my PC except for Factorio respects the control modifier and works perfectly. In the second instance, Factorio works fine.

I'm not holding my breath for a resolution on this, since testing it in the office would require purchasing and perhaps soldering together a custom keyboard, but I figured it was worth a shot.

To reproduce:
1. Acquire a keyboard running the ZMK firmware and set up a hold-tap key with control and escape (use mod-tap).
2. Attempt to use a ctrl+something shortcut - it will fail if you don't wait for 200 ms before pressing the other key.