I’ve also thought about changing the Thumb keys a little. Keep in mind this is only thoughts & theories for now, and will likely change once I get my Model 01’s and try things hands-on.
I do a lot of modifier chording. I’m planing to try using OneShot keys as discussed in the Chording and discomfort thread. I think the idea has a lot of merit. @algernon makes a great case for using one-shot modifiers in that thread and in his blog posts. And as I thought about it, I can definitely see it as being faster than chording. With that in mind, I want the modifiers in sequence so hitting two or three of them in a row is a quick process. So I wanted to place them all next to each other. At the same time I want to prepare for the possibility of doing conventional chording. I remember either Jesse or Kaia saying that the shape of the thumb keys allow for simultaneously pressing (i.e chording) two adjacent modifiers. Ctrl+Shift and Ctrl+Alt are the two most common chording combos for me. And Alt +Shift a close third. This layout should allow for easy one thumb chording of the first two, and two thumb chording of the latter one (as well as Ctrl+Alt+Shift). But again, I’m hoping I can take to OneShot’s, thus making chording unnecessary. If so, I will remap the second Shift key on the left hand to something else.
Again, all subject to change 
Including possibly moving the modifiers off the thumbs.
