Well thought out and interesting, Sieran.

I think, as long as the introduction is blended well and not too abrupt book 2 or 3 is an excellent time.

I think in the publishing game, there's probably too much pressure to start out in book 1 with sexual and gender diversity.

If that happened, of course you are going to bring out the homophobes before you had big sales and a single book published, let alone a series.

Also trad publishers tend to be a bit staid, over traditional and cis themselves in what they publish as well.