Are "kinda", "sorta", "oughta" and "sposta" acceptable in formal writing?

Question

I get that sorta, kinda, sorta-kinda (this one I quite like though) oughta and sposta imitate speech but it still niggles me to find them "in print", especially when the overall tone is formal.

Occasionally, I have read detailed answers on EL&U in otherwise impeccable, faultless English, containing any one or more of these ‘dialectal’ expressions. I have asked myself what was the aim of the writer, when the rest of the answer is formal and technical in style.

Outside of EL&U are there examples of formal and scholarly texts which contain any of the above expressions? And, ironically, are these forms considered ungrammatical/non-standard when used in informal writing but perfectly acceptable in formal writing when written by an academician?

Tidbit
Google Ngram shows that kinda has been enjoying a massive rise in popularity since 1982, while the other colloquialisms have remained steady.

Answer 1

I guess I kinda can add something of value here. I'm AmE, and I do sometimes use those colloquial, non-standard spellings, such as "kinda", "sorta", and others -- intentionally. (There are other non-standard spelt words which sometimes are used for similar intentions: gonna, gotta, hafta, oughta, supposta, usta, wanna. Those examples happen to have the infinitival marker "to" incorporated into the word.) These kind of words usually have the exact same meaning as the more standard spelled expression (but not always).

Anyway, the reasons why I, personally, might use them are:

• explicit hedging because I know that I'm over-generalizing or slightly misusing a technical term. (And so, for informal discussion, I sometimes use these words instead of more formal hedging expressions around those "misused" technical terms to indicate that I'm using the technical terms loosely.)

• implicit hedging because, although I think I am saying it right, I am too lazy to verify by looking it up, and so, to play it safe, I put in an informal hedge word, just in case.

• to give the post an informal feel, especially if I've been droning on like it's been a lecture.

• to indicate that I'm an AmE speaker, and so, the reader should take that into mind when reading my posts.

So, those are my excuses.

(ASIDE: Recently on another forum, I've used colloquial spellings and non-standard dialects when engaging in a grammar discussion with an arrogant, know-it-all pedant troll who was completely wrong. Oh, I also did a whole bunch of copula droppings (e.g. "You so stupid")--the pedant troll was so naive that he didn't recognize it for what it was.)