There haven't been any comments here the last few days, but we plan to wait until February 22 (23:59 UTC at the earliest) to give people a few more days to weigh in before we take any further steps or decisions.
Topic on Extension talk:TemplateStyles/Q&A
(That would be now.)
TL;DR: The team will go ahead with option 2 without magic subpages, "Store CSS in a separate page".
As someone who has no particular stake in the outcome of this (I was merely asked to keep an eye on the discussion, can't say that I have an opinion here), I told the team that my reading was "no real consensus either way", with arguments on both sides, the main disagreement probably stemming from different focus – on the one hand future development (ease of moving MCR as a strong argument; conviction that the main drawbacks of separate storage are temporary and will be addressed reasonably soon anyway), on the other hand the here and now (ease of editing right now; unwillingness to take MCR into account because you never know how long it takes before something is done). It's difficult to talk about refutation of arguments since the positions roughly align with different priorities and views on what to expect from future development. Since they had to make a decision and seemed to have a strong conviction about what would be the best solution – store CSS in a separate page – my reading of this was that they should ago ahead with that, since there wasn't enough guidance here to do things in another way.
(Also, from a !voting perspective, slightly more persons involved in this discussion seemed to favour separate storage.)