I am trying to have long equations (i.e., equations that go past the point where normal text wraps) wrap in the same way that text does in Obsidian.
For example, the equation $2Fe_3Si_2O_5(OH)_4+6Mg(OH)2 → 2H{2~(aq)}+2Mg_3Si_2O_5(OH)_4+2Fe_3O_4+4H_2O$ extends past the limit where normal text wraps, and while I can see the full equation if the Obsidian note is full-screened, this equation will be cut off by the side of the note window if I have multiple notes open (side-by-side) or if my Obsidian window is not full-screened.
AFAIK you can’t force MathJax to automatically wrap inline equations. But in this case I would use display math (notice two dollar signs) instead of inline math syntax:
it is due to the fact that line-breaking hasn’t been ported to v3 yet, so there is no code in v3 to do line breaking yet. it is on the to-do list, but the font update that is currently underway come before that.