There's something I've noticed about writing Thai. When one wants to indicate a word that is drawn out, like in the title of this post, you typically multiply the last consonant of the word. As in, คิดถึงมากกกกกก "I miss (you) soooooooo much". Now, in both languages, the sound you're actually drawing out is the vowel. That's why it's interesting, I guess. You might expect it to be written มาาาาาาก. And indeed, you can find instances of this on the internet--or a combination of both, e.g. มาาากกก--but not many, versus hundreds of thousands the other way. The exception to this is words that have no final consonant (a.k.a. open syllables). For example, อย่า would be อย่าาา, มา would be มาาาา, etc.
So, I wondered, how do you draw out syllables like รู้ in writing? It's an open syllable, but you can't draw extra vowels without extra consonants. And รู้รู้รู้ would mean repetition of the whole word, not drawing out the vowel. As it turns out, the internet contains instances of both รรรรรรู้ and รู้รรรรร. Which is predictable, since non-linear vowels don't have a obvious strategy. For โอ้โห, the results are similar both โโโอ้โห and โอออ้โห among others.
Of course, this is informal writing, and so there's probably no real standard. I have seen words drawn out like this in advertising. A billboard for condos near where I work that says in huge letters, โดนนนนนสุดๆ (โดน here is short for โดนใจ, "to be to one's liking").
As an exercise, I tried Googling the word มาก with varying numbers of extra ก's. And no matter how long I got, there were always results, with such expected culprits as "น่ารักมากกกกกกกกกกก", "สวยมากกกกกกกกกกกกกกกกกกก", "เยอะมากกกกกกกกกกกกกกก" etc. I also discovered that Google has a limit on the length of a single word. It's 42 characters. After that it tells you X is too long a word. Try using a shorter word. It still carries out the search, though. So I tried even longer. And longer. And longer. I was still getting around 26,000 results! And then it happened: Google just couldn't take it anymore. It told me "Bad Request. Your client has issued a malformed or illegal request." The internet cops are knocking on my door as I type.