It would be super cool if you could add the ISO variant of the Spanish
You can use US Int, Fin/Sw/Dan Int, and other European locales to write in Spanish. I write in Sp extensively and I have never used neither Spain nor the Latin version of SP layouts.
Kinda wanted to know how, and I mean if u can put a practical example, specially for áéíóúçñ which are keycaps that has no legends and you just have to pretend they are there.
Or maybe you use EURKey software idk.
In Spanish you don't have fixed keys for áéíóúü because you have a separate ´ (just besides the ñ key), you press ´ and then the vowel you want to accent so you get á for example, for ü you have to press shift+ ´and then u (or any other vowel for that matter), both ñ and ç have separate keys because they are letter by themselves, ñ is not an special n and ç is not an special s.
In order to type with different keycaps you just have to map the keyboard to (for example) iso-es layout and whatever keycap you have over the mapped ñ key will type an ñ, I have a iso-gb layout keyboard and I think it has : ; where the ñ should be so I press that, I guess you just have to know where are your keys at and there you go.
The thing is, imo, that it looks less aesthetic and has less of a custom/premium/exclusive feeling, you spend ˜300€ on a keyboard to not get keycaps in your language, most people won't be up for that. Anyway, finding good Spanish keycaps is a rabbithole by itself, most don't have all the proper keys, or mix up latin american and european distributions, don't have the brackets on the correct side, forget the E with the € symbol, or don't include a ç
TL;DR memorize the keyboard, set iso-es, put whatever keycaps you want