I previously posted my custom layout keyboard which I use at home. I got fed up of the different layout at work so I made the same thing to have consistency. Really happy with the result. I'm trying to set up macros now to make annoying tasks at work faster.
Split space bar was mostly the point of this (and also split backspace, split right shift and an added key at the bottom right). I only ever use my right thumb for space so the left key is backspace and the middle key is an additional function layer.
Oh yea, I’m there with you. I’ve got a two space bar keyboard and use the left side as the a mod key that provides a whole keyboard of custom macros and has completely changed my keyboard. It totally through me down the custom keyboard rabbit hole. I would have fallen in if I had the funds for it, but alas it will have to wait!