Thanks to everyone here for the suggestions. Key pitch is now 19mm, I've removed the top row and added a second index column.
I'm not really pleased with the arrow pad placement, but I haven't found any better place yet.
I'm still working on the layout...
I always program my arrow keys to have PgUp/PgDn/Home/End, so technically they do two things 😅. I'm working on the layout and all of the layers are crammed already. I may have to abandon features tho, the way I see it I would need to free 8 keys on the function layer to make things work.