I really dislike shortcuts with `[` and similar keys. Design software also tends do use them. On a Portuguese keyboard layout[1], I need to press ⌥8 to get `[`. So shortcuts like ⌃[ become ⌃⌥8, which in vim produces `8`.
This way I can use all the default US-based shortcuts for emacs/vim/... while still being able to easily type the special chars for my native language, e.g. pressing AltGr+o results in 'ö'.
This method is slightly inconvenient for typing long texts but for me it's still the perfect solution to such problems.
Examples:
ä - AltGr+" a (the double quote looks visiually like 2 dots)
ç - AltGr+, c
õ - AltGr+~, o
and so on. I found this solution very practical, even if quite late in my life (went from German QWERTZ, to French AZERTY, to end up with QWERTY), because QWERTY is available everywhere, even if I have to work remote through Windows computers, and it is much much friendlier than AZERTY/QWERTZ. Additionally it gives me to write with the same layout German, French, Portuguese, etc. And it is very easy to remember how to get the accents, because the used signs are visually close.
But anyway, EurKEY would be a sane standard in Europe, instead of the hellish borderline-inusable national standard keyboards...
For every shortcut you can imagine you can find at least one keyboard layout out there where it's inconvenient.
Just get over the crappy nationalized keyboard layouts and use US English keyboards like all programmers do!
I can type French + English + Romanian just fine and comfy (would also work for Spanish + Italian fine, northern languages might be a bit of an issue...), with all the accents and special chars of each language, on a US-English layout keyboard that also has `[` and ``` (backtricks) and all the 0-9 numbers available one keystroke away. Mac keyboards work fine by default, the Windows ones might ned fiddling around with picking US vs US-Intenational and windows quote character settings until you get it right.
Western European keyboard layouts (except British) are just plain broken imo, you can't need more than one key to type a damn `[` (array access), or force ppl to use Shift to type numbers, wtf.
Otoh, typing Lisp code on a French keyboards is kinda' cool in a way :P