I write scripts in Word, formatted in like, list form, which I think makes it pretty easy to read. It was somewhat of a trial and error process with my artist to figure out how to most easily write it though, and in the end it was the list way, and then one episode pr. document.
So like, the numbers corresponds to the panel number and such.
Idk, I think with enough space and formatting, word is great xD
And not having everything in the episodes themselves is good as well.
Other than that, I use excel for everything else (Descriptions, character descriptions, world building and such) than the story and the scripts.
That said, I've only ever written one script that actually is a webtoon, and some other scripts that haven't seen the light of day, so I might just have some hurdles with my current way of doing things, that has yet to come. Idk. So far this is fine:
(This is a screenshot from one of the poor scripts I haven't been able to do anything about, but basically, the number is the panel number, the a b c is dialogue, and if I had gotten to the SFX portion, they would have been in bullet point where they would fit)