To be fair, all Japanese I know I've taught myself so I have no idea if any of it is actually accurate or not (I mean, I assume
some of it is, but y'know). I always type out the long vowel sounds no matter what (unless it's a place name that officially doesn't use them, like Tokyo vs Toukyou, although I always want to type Hokkaidou and have to stop myself). It's why I will never, ever type things like "Sato" or "Kudo" because they don't reflect the long vowel sounds. I get that a lot of the time Japanese people themselves don't Romanise them, but imo I think that's a case of English speaking peoples not putting much thought into the system originally.
I also think that keeping long vowel sounds as accurately as possible helps people who are learning Japanese. For instance, if someone were to type くど and select the first kanji option that comes up, they'd get 久度, which is completely different than 工藤 -- the option you get if you type くどう.
I have a very strict Romanisation system in my head and I'm not sure if it's all entirely accurate and I know it'll probably piss a lot of people off, but it's the way I do things. I also get extremely annoyed whenever people leave loanwords (especially shortened loanwords) untranslated. An example would be people who Romanise ダイヤ as "daiya" even though it should be "dia" since it's short for ダイヤモンド, or "diamond". It happens all the time with anime titles -- a major example would be とらドラ!, which is officially Romanised (and Romanised everywhere) as Toradora! for symmetry... However, the ドラ is from ドラゴン (dragon), so it
should be, by all means, Toradra!. But if I ever called it that I'd be laughed at, even though it's more accurate, god dammit. Something that's more close to home is people who type "Harosute" for Hello! Station. We have a perfectly good English equivalent... it's H!S. It's even shorter! ハロステ is short for "Hello! Station" obviously, we don't use Haropuro for ハロプロ and use H!P instead, so the situation should be the same here. But it's not because people can't follow rules.
TL;DR: Romaji and Romanisation in general are fucking dumb and people don't follow the rules enough and break consistency all the time and it pisses me off more than it should, but I'll be damned if it isn't one of the things in this world that aggravates me the most. The solution is clearly to get rid of Romaji and just use kana, but that's not user-friendly and also if you use kana instead of Romaji when writing/typing English you come across as a pretentious douchebag, lol.
God dammit here I am talking about languages again...