Something like this? The heavy stagger is great, 42 keys is almost perfect, but the thumb placement is – for me – horrible. Having to move my thumb to practically under my palm is just terrible ergonomics.
This thumb layout reminds me more of the ErgoDox variants, and is far better placement. Is there a layout close to this?
Ah it seems that I misunderstood the image you provided. I have the outer thumb keys mapped to keys I don’t often use (GUI and Alt) so I’m okay with them.
Maybe try looking at all the builds people share on kbd.news? I’ve also heard that it’s not super difficult to modify open source designs and order the PCBs yourself, but I haven’t tried it.
Hope you can find something that works for you