On the one hand, yeah, footnote Markdown does NOT play nice if you are applying a readmore, and I figured this out by about day 3 of chosting. It's fine, <sup>1</sup> & 1. manual footnote don't have any problems and really aren't much slower to write!
On the other hand, it's very possible that the kind of choster who uses footnotes has tremendous overlap with the kind of choster who manually applies readmores to their posts, and it's thus plausible to me that these two Markdowns clotheslining each other at the HTML level comes up way more often than you'd initially think.
Anyways the relevant eggbuggpagge is over here if anyone wishes to bump it.
I feel like this should be solvable by using a custom css read more using details and summary
