Firstly, I'm not aware of a documented "superfluus" usage in English. Maybe we have to go back more than seven or eight hundred years to find it?
Secondly, "-ous" (like "-ose") functions generally as an adjective-forming suffix and is derived from the Latin "-ōsus"; it does not correspond to, and is not an expansion of the the "us" ending in "superfluus". "superflous" can be regarded as a derivation of "superfluus" that has been regularized with the "-ous" ending to make it recognizable as an adjective. This has happened with other words, like "continuus" and "contiguus". In contrast to these, many "-ous" words in fact some from ancient "-ōsus" counterparts, like "numerous" from "numerōsus".
The case for reviving "-ōsus" in English isn't very good; since neither of its "s"s are silent, it calls for a change in the actual spoken words, rather than merely spelling. Plus, it is unfamiliar to English speakers.
The case for creating a class of "-us" adjectives to restore Latin spellings like "contiguus" or "superfluus" is also not very good. It may be shorter, but adds to the proliferation of suffixes. To retain the pronunciations, we need "uu" to be rendered as the diphthong /yuə/ or /uə/, the precedent for which is scarce (being apparently limited to just "continuum"?) I'm not aware of any dialect of English in which such a restoration attempt has taken place, unlike "color" and "neighbor".
Firstly, I'm not aware of a documented "superfluus" usage in English. Maybe we have to go back more than seven or eight hundred years to find it?
Secondly, "-ous" (like "-ose") functions generally as an adjective-forming suffix and is derived from the Latin "-ōsus"; it does not correspond to, and is not an expansion of the the "us" ending in "superfluus". "superflous" can be regarded as a derivation of "superfluus" that has been regularized with the "-ous" ending to make it recognizable as an adjective. This has happened with other words, like "continuus" and "contiguus". In contrast to these, many "-ous" words in fact some from ancient "-ōsus" counterparts, like "numerous" from "numerōsus".
The case for reviving "-ōsus" in English isn't very good; since neither of its "s"s are silent, it calls for a change in the actual spoken words, rather than merely spelling. Plus, it is unfamiliar to English speakers.
The case for creating a class of "-us" adjectives to restore Latin spellings like "contiguus" or "superfluus" is also not very good. It may be shorter, but adds to the proliferation of suffixes. To retain the pronunciations, we need "uu" to be rendered as the diphthong /yuə/ or /uə/, the precedent for which is scarce (being apparently limited to just "continuum"?) I'm not aware of any dialect of English in which such a restoration attempt has taken place, unlike "color" and "neighbor".