I didn’t express myself.
You are right Nate, on journals with langs with mixed charsets the UI will work great because users will usually like to write their name in different languages.
But, what I wanted to say is not this.
I’m talking about journals sharing same/close charset (english, spanish, italian, french, portuguese…) that usually appeal to users of those same langs so 99% users won’t require to write their givenname/familyname in one lang and will find the UX confusing.
Some years ago I posted in gitHub explaining why I though it need to be rethought, but now I can’t find it. 
Anyway, in this post (alive from 2016 to 2020. longest post ever?) some fellows explains they are not happy with the existing solution too:
I can’t tell for sure how many journals include langs with mixing chars and how of them share (could we know with all the beacon work fellows are doing?) but I suspect it will be very related with regions: In a brute estimation I would say most of south-American journals and EU will use a single charset, and also for journals with a single lang, and mixure will be more common in boundary regions.
In our service (spain), in 50 journals we use a lot of langs, but one is asking for different charset (they include Chinese). I mean, I know this is just an example and PKP need to think it globally, but I’m just trying to explain that I think the dimension is big enough to spend some time to find, if not a solution, a work-around.
Cheers,
m.