I also renamed the Sym key to 123 in my romanian keyboard, and changed that to an alt key when you are in the second character page (see #5660)
1/2, 2/2 are a welcome additional change.

Well, before the highlighting of the Shift key, I would have liked it :)
But with the highlighting, it feels a bit less needed - and having 2/2 highlighted (1/2 is not) feels strange/duplicated...
Also, I feel the Shift symbol less ambiguous. I could expect hitting 1/2 would output 1/2 :) Because the ... just above the 2/2 will output ..., while I could as well expect it will move me to the ...next... layer :)

Anyway, just a thought. Go ahead if you prefer it that way.

I'd also tend to prefer a symbol over this, too.

I'm okay with Shift, as it's fairly universal, but we also have access to Apple's Command & Alt/Option glyph which might make more sense than shift in this context (the alt one, especially).

At least for people familiar with Apple layouts ;p.

The shift symbol here I can say it seems a bit ambiguous. On the main letter keyboard it makes sense, but on the symbols keyboard it should indicate something that "there are more symbols here". I would go with anything else BUT the shift symbol.

FWIW, I have no strong opinion on that subject. I'd vaguely prefer a symbol (because I also find that it's enough since the HL tweak), but that's it ;).

I think any symbol would be significantly less clear than a simple 1/2 and 2/2. Shift would at least be consistent and therefore better than anything trying to be too clever.

I'm still in favor of this proposal. Has it grown on you guys by any chance @poire-z @NiLuJe? ;-)

Well, I didn't give it a chance to grow on me :) but as I get now that it applies only on the symbol/number layers, it's less drastic that I initially thought. So go ahead.