I received an assembled WKL KMAC a while back and noticed some troubles with KRO, but really procrastinated in figuring out the issue because I didn't have any Allen wrenches to open it up. (I only just received a set of them today, and it looks like 5/64" works.) I have the "KMAC WOW 1.3" PCB version.
Basically, the issue is that I'm not properly getting more than 2KRO. More specifically, I'm getting this one particular strange issue with alpha keys where if I hold down 2 characters on different rows but on the same "column", then hit a different character on one of those same rows, an extra keypress of the related-column-key of the row not typed is registered. (This is probably confusing, but read on.) It's a little problematic due to my typing style/speed.
For example, if I'm typing the word "just" really fast, there's a chance I'm registering both "J" and "U" simultaneously while I'm hitting the "S", the "W" comes in and I get "juwst". Or if I'm really on a roll on typing fast, then as I'm hitting "T", the "G" can come in quickly too and I can get "juwstg". (This is hard to screencap on keytest applications since I have to hit the PrtSc key while typing, but on a QWERTY layout you can see the relation between "W"/"G" and "S"/"T" respectively.) Additionally, modifiers can get really weird - like RAlt being registered when hitting spacebar, or Ctrl+Right Arrow combo not registering, and so on.
That said, the LED keys - WASD, F1-F12, Esc, Caps Lock, etc. - did seem to be fine and get 6KRO when isolated from any other problem key.
Because it was a KRO issue, I thought whoever built this might have just not soldered on any diodes, but I found some interesting things going on when I finally opened it today. It first looked to me like there was both SMD and through-hole diodes soldered on, ...
... But it seems as though what's in each switch is a jumper wire. My Google-fu is a little weak in finding out reasoning behind a choice like this; if I was building this from scratch jumper wires wouldn't even cross my mind and I'd just do either SMD or in-switch/through-hole diodes (and not both).
Before I get my hands messy with anything, I'm just wondering if there's any manual-soldering solution to this, or if it's just some kind of debouncing problem that can be solved through firmware adjustments. Anyone have any thoughts?