At the risk of provoking a burst of laughter, the way my company used to handle mathematical formulas was to use a high-end math symbol Postscript font and create all the formulas using
Adobe Illustrator. We selected a drawing app in order to get extremely fine control over symbol placement, scaling, and positioning.
My former business partner was a typography expert that didn't believe in automating certain things when it came to characters or symbols.

His approach was to treat mathematical formulas as
pictures rather than as text since
they would never change once they were created.
After a formula was created, it was saved as a (scalable vector format)
illustration so that it could be dropped in and re-sized as and where needed. This was a major up-front pain to do. But once the formula "art" was created (and proofed/approved) it was very easy to catalog for future reuse.
We did a 1200-page technical manual for a Fortune 10 company where we built a library of about 200 formulas. This came in handy down the road when we were contracted to produce some additional manuals.
Having a library of the requisite formulas allowed us to hold down our costs and shorten our delivery times such that we beat out several larger competitors for future editions of this manual. We had a major advantage because we didn't have to redo -
or proof - hundreds of formulas
we didn't actually understand. And because the formulas were art - there was no danger of a typo error creeping in once we had done the initial proofing.
Maybe not the most elegant or 'techy' way to do it. But our approach worked quite well, both for the initial project and its revisions.
