Overall Experience
UI wise, Tapas has some quirks that I'm not into, but as far as getting feedback, Tapas is probably my most "successful" site. I have someone who consistently likes chapters, and I made friends with someone who enjoys my story and vice versa. (Check out coco-ji. Absolutely fantastic writer. Has one Adventure Comedy story and another that's a Thriller w/ Romance.)
I've also made it into two of the community collections, but I'll talk more about that later.
What I Wish I Did Differently
Even if you have a big buffer, it's probably best if you don't do daily uploads. 
Had I not blown through mine, I probably could've maintained the illusion of having a consistent update schedule for longer.
Nothing bad happened when I started off posting in a buncha promo threads, but over time, I came to realize it made me come off as really desperate, even if I used different images/blurbs/etc per post. 
The general promo threads seem kinda useless anyway. It's better to engage in discussion / challenge threads that have something to do with your story.
(Don't post your story in a thread if no one else is. Put your story's link in your bio instead, that way if people are interested in what you have to say, they can still find your story easily.)
Tapas Promotion and Premium
Like I said, I made it into a couple community collections. Tapas Community Discord sometimes hosts events where creators can submit their story based on a certain theme. The first one I got onto was Lucky Finds, which was for stories with under 500 subscribers, I think. The other one was for a Pride Month celebration.
They've also hosted other ones for Supernatural Romance, Horror (iirc?), and a full-blown tournament for Action Fantasy stories. Most of these are only announced on the Discord. I made it so that I get notifications for the announcements channel, since I noticed submitting early gives you a better chance of getting your story featured. (I did both times I got featured).
Both features led to an increase of subs on my story, so it's good for visibility no matter what. However, I'm not certain how much visibility the community collections have since as far as I know, the only way you can see them is through a link posted on the community Discord (checked mostly by other small creators) and on Tapas Community Social Media Accounts (followed mostly by other small creators). Creators having their own stories to create usually means they don't have a lot of time to read, leading to mostly dead subs.
On a more positive note, I've heard that the more staff features your story in community collections, the more likely they are to feature you elsewhere. I also heard staff is more likely to feature stories that post update on a consistent schedule, so there's a tip.
You have to work really hard and really take what's popular into consideration to even have a shot at being premium. There's some genres in the community sections that aren't even featured in premium. If I had to guess, your chances of getting into that section are much higher if your genres match what's already in Tapas's premium lineup (Visual Novel-Based Romance Fantasy, JRPG-based Action Fantasy, maaaybe BL).
Story Promotion
I draw an illustration for each chapter, so when it comes time to promote a new chapters, I post the illustration to my social media accounts along with a link. Has it helped any? [shrug] I'm still figuring this stuff out.
I will say, someone genuinely showing interest in my story got me to check out theirs, which benefitted us both in the end. I've seen people say showing interest in other peoples' work and making friends is a really good way to get traction when you're first starting out. Personally, it feels kinda sleazy to me to think of it as a promotional method, but if you have the time and energy to get invested in other small creators' stories and make friends with the authors, give it a shot.
Your Method
I don't really have much to say. Your method sounds like a good idea, especially since it allows for a consistent schedule.
Why I Chose Tapas
I do actually post on Royal Road. (Not Webnovel though, I heard it's really predatory.) I really, really did not want to post on Tapas at first. I absolutely hated the 15,000 character limit when I first started out (still not a fan). But my story fit Tapas' (Community) niche much better than Royal Road's.
When I started posting to Royal Road, I did so after hearing that it was a good place for sci-fi. And it's better, sort of, but Royal Road's main bread and butter is LitRPG, Gamelit Isekai, basically anything based around a JRPG system. Stories that aren't tend to be pushed to the margins. It's not the fault of Royal Road or its userbase, it's just how it is.
Aside from not being system-based, my story has multiple POV characters, and sometimes LGBT+-related topics come up. Both of these things were not very well-received by Royal Road's audience when I first joined (2021). Thankfully, it wasn't popular enough for the people who would've complained to have ever seen it. But I wanted to find a place where I could find willing readers without having to worry about having my visibility getting tanked by someone getting mad that I didn't warn them about my story having gay characters.
Things have gotten a little better on Royal Road since then, but yeah, that's what finally got me to use Tapas.
