Except those counterpoints aren't great. If there are technical issues then those could still have been worked out for Episode 9 rather than an interlude. If the purpose of the Interlude was to flesh out Zoey as a character and allow you to shape her then why does DPC undercut all that by reducing her to a single variable come episode 9.Well, yes, but only if you ignore a bunch of things that have alraedy been said (not just by me). So first off, the interlude wasn't just to introduce Zoey, it was for legitimate technical reasons (so I saw - again, I wasn't around at the time to hear first hand). Introducing Zoey's backstory and allowing you to shape her character was just a handy way for DPC to do this, while also having a change of pace from the main story (which you'll notice had a different look and feel, other than just in the characters/setting).
In storytelling, you don't always get all of the characters introduced at the same point. It's only natural that some will come along later (and some might fall away, poor Mona...). That doesn't mean that the author has made a mistake. Maybe it was already decided from the off that Zoey would be a later addition, because you know what that would do? It would add conflict later down the line. You get to know your expected LIs, and then you get something blindsiding you just when you're getting comfortable. That's not a mistake, that's just something that doesn't work for you, because you don't like the new option that has been brought in. It's probably no surprise then for you to see it as "wasteful".
You keep ignoring the counterpoints people put forth about the choices, so I won't bother pointing them out to you again.
And sure you don't introduce all your characters at once but as I mentioned that was already done with Josy being properly brought in with episode 4. The issue with Zoey is that introducing her properly at Interlude/Episode 9 is that it's so late (halfway through the story essentially) that if they're meant to be a proper romantic spanner in the works then she's still at a standing start as a character while everyone else is essentially moving towards the finish line. And if DPC's intent was to have her be a spanner in the works romantically, again this is immediately undermined by the ability to go "nah, sorry" within minutes.
It just feels like there's a draft of this where DPC meant for her to be a "Main Girl" but got sidetracked by everyone else and it's too late to properly integrate her. And rather than go "that's a shame, but I have all these characters already" instead they tried to flesh her out with the Interlude but because none of the variables can be retroactively integrated back into the main narrative they don't actually exist to shape the character because, again, it just ends up kicking into Episode 9 with "is Zoey a DIK or CHICK".