Just found a lively discussion. Although dated from April 2019, this is indeed being discussed at the top levels of Mastodon project.
A long topic, including the lead developer's resistance to the request for support (WITH Code included) of Rich Text options (#MarkDown and others, as already supported in GlitchSocial, Pleroma and other #Fediverse platforms).
Eugen is not for it (or we would already have it). But there IS a yearning for more than the Sh1tty plain text. From people who write toots longer than the one liners favoured by old time ex-Twitter heads.
Discussion at : https://github.com/tootsuite/mastodon/pull/10629
Saving this as a place marker, for later reading deeper into it.
#Mastodon needs Better text formatting options. Get on with the times, will we?
Example image included in topic - https://user-images.githubusercontent.com/384364/56579570-ce48ef00-65d0-11e9-9a53-a67c47537d4e.png
A more recent Issue posted at the project's Git, included a proposal for Quote Block -- which is part of what others already have, and do a lot for Forum discussions, for example.
"When responding to a toot, allow to put context (quote/reply) #13876"
https://github.com/tootsuite/mastodon/issues/13876
From this topic, ThibG linked to the older discussion (lively topic, link in the above toot). Screenshot of this older topic included here.