Hi there!
Long time lurker, newly registered. Was not entirely sure if I should post here or somewhere else, but given that Colemak forum seems to be the biggest forum for alternative keyboard layouts (Colemak) I decided to do so here!
I am a long time user of staggered QWERTY keyboards who started to use Dvorak (almost loved it) on an ortholinear/matrix keyboard (Planck) for a few months, then moved on to Colemak (also almost loved it) for another couple of months and finally almost settled on Colemak Mod-DH (brilliant mod for Colemak BTW) until I realized there was one issue with it - lack of "asymmetrical" keycaps for this specific layout. For instance, when you buy printed keycaps in e.g. OEM or Cherry profile, where each row differ from the other, there are usually an option to add a so called "Colevrak" kit which includes a few more keycaps in order to setup a keyboard with Dvorak or Colemak legends, but unfortunately they do not include keycaps for Colemak Mod-DH (which is not surprising given that it is a modification).
The lack of keycaps is of course not a dealbreaker for me but as a user who likes proper legends on my keyboards I started to look for a way to modify the standard Colemak layer to fix similar issues which Colemak Mod-DH takes care of. Simultaneously, given that I had grown accustomed to Dvorak and liked the way this layout approached certain solutions (such as the TH bigram), I decided to combine Dvorak and Colemak in order to create something new.
The rules for this new layout were the following:
1) Retain letters on the rows which they are allowed to exist on given the standard QWERTY, Colemak and Dvorak layouts.
2) Use two of F,J,U,H,T,N on the homing key locations (home row, underneath pointing fingers resting position).
3) Keep ZXCV on the bottom left corner.
4) Move H to a more accessible position near T.
5) Keep almost all of the letters ARST NEIO on the homerow under the resting position of the fingers - if moving one, put it at a comfortable position.
6) Avoid uncomfortable same-finger bigrams.
From 1), a table was created:
Row 1: C E F G I J L O P Q R T U W Y , . ; "
Row 2: A D E F G H I J K L N O R S T U ; / "
Row 3: B C J K M N Q V W X Z , . ; /
Following these rules, I started to experiment while testing my different ideas with the Layout Analyzer Tool on the Colemak Mod-DH Github page:
https://colemakmods.github.io/mod-dh/analyze.html
This was the end result:
, . R P J G F U Y ;
A E S N L D H T I O
Z X C V B K M W Q /
It scores 1.80090 in total with the Matrix layout, which can be compared to 1.88550 for Dvorak and 1.75468 for Colemak. While not as low as Colemak (or Colemak Mod-DH), it does have certain improvements towards Dvorak and as such can be seen as a Dvorak-improvement using some of the ideas behind the existing Colemak and Colemak Mod-DH layouts.
I am far from an expert in layout creation and this was only created after a few evenings of experimenting, but I would very much like to hear what you think of it!