This is a Tsangan/HHKB (split backspace, split right shift) layout following the traditional HHKB layout with a few changes:
The Delete key is mapped as Backspace (HHKB DIP switch 3).
The Alt and Super keys are swapped to put Alt directly adjacent to the spacebar (HHKB DIP switch 5).
The left Super key is replaced with another Function key (HHKB DIP switch 2). Unlike on the real HHKB, this key triggers a different Function 2 layer. (This also helps prevent accidental Super key presses while gaming.)
The Function 2 layer contains reset keys, RGB underglow and backlight controls (in place of the arrow and navigation keys), and media controls (centered around the ESDF cluster).
The Function 2 layer also has the F1-F12 keys mapped just like the Function 1 layer. This is a concession to gaming because it enables these keys to be easily typed with the left hand, without taking the right hand off the mouse.
The leftmost and rightmost bottom row keys are mapped to Ctrl rather than anything more useful because most of my Tsangan PCBs actually have HHKB plates and/or blockers, so there aren't switches installed in those positions.
(KLE)
(KLE)
(KLE)