Option D is better, but not exactly my liking.
Probably make one of the left modifier to be 1u so that the left space is 2.25u? (for GMK compatibility because 2u GMK key is not often)
like this?
but the option A looks better.
Most of custom split keyboard I see (feel free to correct me if I'm wrong, because splits is kinda a niche layout) have another key in between the spacebar.
I have three splits, both of them has 1U in between the space keys and one of them not (this is one is mass manufactured, if I have the chance to have a key in between the spacebar, I would).
In my opinion, the reasons for this are:
- The lower right of the left side of the split keyboard is where the natural thumb rests. If we have two keys easily reachable, it's more ergonomic. If all the modifiers on the left split are all on the left of the spacebar, your left thumb will travel more
- Since both of my splits are using Bootmapper, double action (FN/SPACE in one key) is not available or reliable enough. Thus having individual keys for FN and Spacebar is preferred. This related to number 1 since it's more ergonomic to have two keys near.
- Since not all people use the same hand for hitting the space (I personally use my right thumb when typing, and left thumb while gaming, obviously) I personally don't expect all of the people binds their space keys with space and FN. For me I bind both space keys with space. Thus having an extra key for FN is preferred
And again, this purely my opinion and does not represents major users of split keyboards.
Another thing to keep in mind since it will use QMK, I heard good things with the double action (FN/space) feature. Can someone chime in?
So option D would not be a dealbreaker for me.In my opinion for the layouts,
This post > Option A (because standard 2.25u and 2.75 space keys) > Option D.
Other options, I would not buy, sorry.
So it would look like this (sorry for the lazy layout...) for the left side bottom row.