What I've heard is from Taiwanese sources (so of course that colors it), but they're reviewing the movie positively, and say it pretty accurately portrays the time period. I have no idea. One way or the other it'd going to be biased.

The carrefour I went to the most was in Danshui (we did our weekly shopping there!). I also went to one in Tianmu occasionally, since it was like, right outside the MRT.