urob's pattern on QWERTY: shifted num row vertical top+mid, operators vertical mid+bot. ESC/TAB horizontal off pinky.

Blue = vertical combos (press top+bottom key in same column)
Purple = horizontal combos (press adjacent keys on same row)
ESC (W+E), TAB (S+D), CUT (Z+X), COPY (X+C), PASTE (C+V)
Optional. SYM layer still works. Combos are for quick access without holding a thumb.

Modifiers
Callum: oneshot on layers, no timers, no ambiguity, 2-step for mods
urob: homerow mod-tap with positional + idle guards, 1-step mods, timing-dependent
Ours: oneshot on layers (callum-style), GACS order (Miryoku muscle memory)

Symbols
Callum: dedicated SYM layer, both hands
urob: vertical combos on base — no layer needed, always available
Ours: dedicated SYM layer (Miryoku) + optional combos on base (urob-style)

Numbers
Callum: tri-layer (awkward), scattered layout
urob: smart-num auto-toggle (tap once, type numbers, auto-exit)
Ours: single thumb hold (comfortable), numpad layout

ESC
Callum: on SYM layer top-left
urob: combo W+E (horizontal, off pinky)
Ours: combo W+E (same as urob) + combo SPC+TAB (thumbs)

Swapper (alt-tab)
Callum: custom QMK behavior, on NAV
urob: tri-state ZMK module, on NAV
Ours: TODO — add via zmk-tri-state module