The more I think about it, the more I think, in its current state
mobile should not collapse sections by default. If you really want to
find a lower section, scrolling down the page and being able to
collapse a section to see the next one is easy, yet if you just want
to read the article in its entirety it is annoying to have to click to
expand a section.
Since we currently load all the HTML for the content of a page it
seems silly to hide it (although we should certainly rethink this if
we ever begin to lazy load sections)
We ran event logging on toggling a while back [1] and the data showed
as you got down the page, it was less likely a section would be
toggled opened and read.
I would propose we keep toggling enabled but change the default of all
sections to be open rather than closed.
This also removes the existing risk of a flash of unstyled content and
enables the ability for users to do find on this page.
We should at least run some kind of A/B test that rethinks this.
Thoughts?
[1]
https://www.mediawiki.org/wiki/Event_logging/Mobile#Section_toggles