I really like your point Chris in regards to the difference between the shortcode and the embed code. I wonder if there is a potential to build on Martin Hawksey’s TAGS work to smash the different parts together in Sheets rather than manually copying the embed code for each Tweet. Something like this:
=“<blockquote class="twitter-tweet" data-lang="en"><p dir="ltr" lang="en">”&text&” — (@”&from_user&”) “&source&” “&created_at” <script async src="https://platform.twitter.com/widgets.js" charset="utf-8">”

I still need to think about how to accommodate “twitter-tweet” so that Sheets reads this as text too.
Doing it this way would allow users to download a list of their tweets and potentially paste the IDs into tags and then generate the embed code.