We already have a workaround for this. See modsecurity_workaround.

Ack, I already did this change for modularisation and cns_warnings. Part of me wishes to keep the change for another reason... multiselect takes up less space on the screen. This is especially important for cns_warnings as it loads content / points ledger records from the last 7 days. Even though there is a max, that's still a lot of tick boxes especially on mobile. And it makes the screen very long.

But then again multiselect is also not as mobile friendly. Hmm... I may need to think this one over.

I would say if there is a good native solution that isn't hacky, that doesn't require our hack (modsecurity_workaround), that's better. Less hacks is better.
If multi-select doesn't work well on mobile that's interesting, but I think fundamentally there's no reason that shouldn't work well - so maybe mobile browsers need to be better.
Or maybe down the line we need to have some kind of abstraction over multiselects.
I think multiselects are good.

I'll check into it. I still need to replace my phone. I'll hold this issue. Once I have my new phone in, I'll see how easy multiselects are. If they're acceptable on mobile, I'll resolve the issue. I would test it in my desktop browser but I want to understand the UX ease of use as well... e.g. the physical interaction on the phone screen of selecting stuff.

I just kind of think on some level the wider development community shouldn't jump through hoops if Apple/Google etc haven't made a proper web UI for multi-selects. There's no fundamental reason why that should be hard. If everyone just doesn't use a part of the web standards base because the big companies can't be bothered to support it properly, it enables that behavior.

That's me putting principles about practical UX though.

I think we've done enough on this issue for 11.0 for now. Modularisation and cns_warnings has multiselects. Those were the big areas.

Actually, we also need this on addon install screen and on file integrity scan. (Problem with file integrity scan is it's part of installer which uses a minimal interface).

Added ModSecurity workaround for modularisation page and addon install page.

Issue rejected for file integrity scan. It cannot be implemented reliably.