To repeat, I don't especially like the "oo" in "Toosaka" here and as such I am not voting against this proposal.
Despite that, I would very highly support we stick to our general policy of following a standardized romanization system, since not doing so is rather anarchic, and we'd need a ridiculous number of aliases to cover all the ways people can, have, and do romanize Japanese in an ad-hoc manner.
For this reason, in general I also still support us using a standardized system over the "official" romaji spellings of native Japanese names. More often than not kanji or kana will be used, and the "official" romanization be an obscure case (often without much thought). In most cases, following the standard system for romanizing the kanji or kana will make more sense than following an official non-standard romanization scheme. Many Japanese people don't really seem to care what romanization system they use (especially since in practice they are used pretty infrequently), but that causes all kinds of confusion on our side. I'd be adamant against us switching "shi" for "si" or "tsu" for "tu" even though both are very common "word processor" styles of romanization (they also lead to bad pronunciation).
That said, (also mentioned in the old referenced topics) "おお" -> "oh" *is* a standardized romanization scheme, just not the one Danbooru decided to go with back in the day. In particular, the official system used by Japan for personal names in passports allows for "oh" (a modification of the Hepburn standard for Romaji). The passport system isn't perfectly consistent though since it also allows "oo" and "ou" (the latter I'd say still better for romanizing "おう"). It would also allow for oddness like "Tokyo" becoming "Tohkyoh" which looks really dumb to me.
I'm not sure without completely tossing the idea of a romanization standard entirely (which would be a bad idea), or poking in a bunch of exceptions (not great), that you'll ever get everything looking good to the majority of people though.
I sort of think that what we have works well enough, unless we want to go back to deciding the best romanization system for us again. If we did, I'd be fine with the above mentioned "passport" system, which would be a pretty minimal change at the possible expense of a bit of internal consistency.
This all being said is the reason that despite personally preferring "Tohsaka" to "Toosaka", I'm still not voting in favor of this alias proposal either.