ZMK Layout Compare

Callum: Clean base, no mods anywhere. Dedicated shift thumb. NAV/SYM hold-only (no tap output).
urob: Homerow mod-tap with positional constraints (left mods fire only with right keys). Smart-num auto-toggles. Magic-shift = tap-repeat + sticky-shift + caps-word in one key. Shifted punctuation (comma→semicolon etc).
Ours: Clean base like Callum. Layer-tap thumbs like Miryoku (SPC=NAV, ENT=SYM, BSPC=NUM). ESC via left thumb combo. TAB is plain for now.

Callum: macOS-centric (cmd-arrows, desktop switching). Swapper (SW_WIN) for alt-tab. Media keys mixed into NAV. Oneshot SCAG order.
urob: Swapper on top row. Ctrl-backspace/delete (word delete). Homerow oneshot mods on left (GACS). Cancel key on right thumb.
Ours: Callum's left side (swapper, tab-switch, desktop-switch, vol, media) + Miryoku right side (arrows, home/end, clipboard). Oneshot GACS on left homerow (hold = normal mod for repeat actions like word-delete). Windows shortcuts: DSK = Win+arrows, TAB←/→ = Ctrl+Shift+Tab / Ctrl+Tab, SWAP = Alt+Tab via tri-state.

Callum: Symbols on both hands — paired brackets across split. ESC at top-left. Oneshot mods on right homerow.
urob: No SYM layer at all! All symbols via vertical combos on base layer (press two vertically adjacent keys). Top row = shifted numbers, middle = brackets, bottom = operators. Always available without holding a layer key.
Ours: Miryoku-style all symbols on left. Right side = oneshot mods (SCAG). Right side is mostly empty — room for expansion. Missing: ( ) were on thumbs before, now gone — could add as combos or somewhere on the layer.

Callum: Tri-layer (hold both thumbs). Dvorak-scattered numbers. F-keys embedded. Oneshot mods on both homerows.
urob: Smart-num auto-toggles — tap to enter num mode, auto-exits after non-number. Numpad layout (7-8-9 / 4-5-6 / 1-2-3). Homerow mods on 0-4-5-6. Very clean.
Ours: Single thumb hold (BSPC). Miryoku numpad with extra symbols (brackets, operators). BT/system on right — should probably move to a separate system layer (see discussion). 0 and punctuation on bottom-right.

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

Grey = Miryoku's 6 thumbs (chocofi). Bold outline = our 4 thumbs (sweep). Dim = keys we lost going to 4 thumbs. Where did they go?