Since the web version is considered a reference implementation, such spoilers shouldn’t work in apps, too.
In the case of this spoiler, it’s likely due to inability to tell apart head and content, those must be on different lines: ::: spoilerheadersomecontent ::: will not render, as no one knows where to split
Side note: why do spoiler tags actually work in some apps, but don’t work in the web version at all? Seems like a serious oversight.
Since the web version is considered a reference implementation, such spoilers shouldn’t work in apps, too.
In the case of this spoiler, it’s likely due to inability to tell apart head and content, those must be on different lines:
::: spoiler header some content :::will not render, as no one knows where to splitOn Boost, neither of these things work.