Denizens of Math.SE may be familiar with a device there for drafting long, complex edits to Answers.
A thread of community wiki posts exists on Meta-Math.SE, Sandbox for drafts of long, complex answers. Users mark an existing Answer on that thread as Done when they are finished with their Edit, and subsequent users are then free to recycle that one.
Since SciComp.SE also uses MathJax formulas, I can easily see a similar need for such a mechanism here, esp. as the site matures.
The "rules of the road" established at Meta-Math.SE for sandboxing complex edits have been honed by experience, so I'd favor adopting them essentially without change. I stuck the feature-request tag on this because it applies in spirit, and furthermore it seems to me that MathJax is not enabled on Meta-SciComp.SE (if so, that would require help from the powers-that-be).