Keyboard layers

Karabiner-Elements · symbols on Tab, numbers on Right Option, Esc/Ctrl on Caps Lock
Brackets
Operators
Other

Hold Tab → symbol layer

Tap Tab alone = Tab · small letter = key you press
tabhold
q
w@
e#
r$
t%
y\
u^
i&
o*
p|
[
]
capsesc·ctrl
a
s
d+
f!
g~
h_
j(
k)
l{
;}
'
shift
z
x
c
v
b`
n=
m[
,]
.<
/>

Hold Right Option → numbers

Top number row not needed
caps
a1
s2
d3
f4
g5
h6
j7
k8
shift
z
x
c
v
b
n
m9
,0

Tap / hold keys

caps lock
TapEscape
HoldControl
tab
TapTab
HoldSymbol layer

UK (British) input source: Tab + E sends ⌥3 so it still types #. Caps Lock is optional on every layer key, so shouted caps won’t break the layer.

Find a symbol

Brackets
(Tab +j
)Tab +k
{Tab +l
}Tab +;
[Tab +m
]Tab +,
<Tab +.
>Tab +/
Operators
=Tab +n
+Tab +d
!Tab +f
&Tab +i
|Tab +p
^Tab +u
*Tab +o
%Tab +t
Other
@Tab +w
#Tab +e
$Tab +r
\Tab +y
_Tab +h
~Tab +g
`Tab +b