I'm rough on the math cause I don't have the billing sheets in front of me, but the other person was pretty close.
The team I managed was me, functioning as frontend lead / architect / engineering manager as well as individual contributor. I then had three junior / early mid-level frontend engineers working with me.
I was pulling 40-60 hour weeks (contract so I didn't mind, just meant more money), the other devs were between 10-40 depending on how much work I could lay out in a sprint. Timezones were Taiwan, somewhere in Europe can't exactly recall, NYC, and California iirc.
That accounts for the frontend. There was a data system that was mostly built when I showed up, by one full time engineer at the startup. So that would be another 40 x 4 x 9 engineering hours on whatever he was working on in the meantime.
Then there was an API that would middleman requests to the data system and build out models and handle customer accounts and shopping carts and other data adjacent requests. That was one full time backend engineer over whom I didn't have responsibility, so add another 40 x 4 x 9 for that.
Finally, the designer was just the CEO. He would draw things up on figma and I'd slice them into frontend tickets. Now that I think about it I think the API engineer was consulting the same designs as he built out the API, I'm not remembering exactly.
So technically my original estimate is just for the frontend, it cost more when considering the whole system.
We "released" every merge into the main branch, internally. The CEO would constantly be giving feedback. It caused some friction occasionally, the classic "right the alignment is slightly off but what do you think about the actual interaction" type shoulder bumps, nothing major. Good feedback loop that basically daily aligned where I should be directing frontend priority.
There was a major customer facing release where a couple core customers were brought off the no code platform onto the new system, that cooked for about two weeks while we collected feedback and engineered against it, then another major release where I took advantage of the respite to do a major rewrite of the naively implemented request management system and fixed up some auth stuff, then another big release and then everyone else is brought over.
I still work a couple hours a week on the projecy but no longer as a leader. Looks like releases are still just kinda whenever, which I think is fine. There are "sprints" and have been the entire time but always quite informal.