ePub first left hand page blank in Apple Books

(Sigh... I had a long answer composed and then switched to EPUBreader to check something, and closed the whole browser when I was done. Don't ya love it when that happens?)

The short answer here, which I will condense from some speculation in my first draft after doing some experimentation, is that the "blank page" appears to be a reader function, a gap inserted when the reader paginates the file to put the start of content on the first (virtual) righ-hand page of the display. This might be partly for esthetics, to give an expected sequence similar to a print book, but I suspect the more important reason is to start pagination on a recto page, as is universal in all books larger than a pamphlet.

I looked at a few EPUB files and can't identify any blank page structure in the content file — that is, ID is not "inserting a blank page" — so pending a little more code-level experimentation, I'd say it's a reader feature and not in any way easily overridden. (Even EPUBreader, the browser-based tool that does not rigidly paginate most books, puts a blank page in a tiled layout there... so.)

Keep in mind that pagination in reflowable EPUBs is entirely virtual and entirely handled by the reader code, settings, and user preferences. There is no standardization for these esthetic/presentation details — it's as if two different publishers use a different page size, margin, font, type size, line spacing, etc. But that blank page after the cover image seems to be universal... so I'd just let it go.

Going to try a bit of code editing just to satisfy my own curiosity, but for now I'll maintain there's nothing actually in the book content creating this phantom blank page.

ETA: There is a bit of essentially empty code at the start of the EPUB content file, but removing it has no evident effect; it does not remove the 'blank page,' at least. Of the four or five readers I have at hand, all insert that page following the cover graphics... except, curiously, Kindle Previewer. So there ya gots it... it's a reader function. Probably no way to override it short of perhaps some JScript, and maybe not even then, given the variations between readers.

Not sure if it helps - but in order to have left page starting on the left - you need to set START PAGE NUMBERING AT in the Section options to "2":

Then start a new Section: