I always type into an MS Word file. That way grammar and spelling is checked by the program. That helps a lot. Plus, I have a back-up in case the platform closes or doesn't save right. You want to keep a copy of everything you write. That's very important. And back up the copy. It saves you from a laptop crash.
My current serial novel was written on two other platforms, Vella and Radish Fiction. All of the episodes were written in Word and then cut and pasted. I basically have different editions now. Each one improves the next. But I have copies of each one. You can even back-up a copy by emailing it to yourself. I've seen so many stories of authors being upset when their laptop crashes and they lose all their writing. So, important to do back-ups of your laptop too.
As far as posting, on Vella, I had the whole manuscript done as a draft. I had an editor look it over, and as I did the rewrites, I posted them as an episode. I didn't get to finish before Vella closed beginning of this year. I was about 3/4 of the way through. SO, when I switched to Radish Fiction, I could polish the episodes up to where I left off on Vella. Then, for the last 1/4 of the book, I did the rewrites from the editor to finish the novel. While I was doing the rewrites on Vella too, I worked with an serial editor per episode as well, which is why it was taking longer. But Vella just didn't last long enough to finish my Kpop romance.
For reference, here it is. Since it's done, I'm releasing daily eps in November. December will have eps 3 times a week. I'm adding at least one extra episode, maybe another, to this Tapas edition. I have ideas for a sequel with maybe other band members. Hoping to get support here to continue on. It has been over an eight year journey so far.
Good luck with your writing!