reflowing content inside MathML token elements

Sometimes a token element's content can horizontally overflow the current page width, especially when the page is styled with a maximum width. What is the right strategy for reflowing such elements? (especially <mn>)

If the overflowing text node was in regular HTML, one could use the CSS word-break property to induce a break. Currently that property doesn't successfully act on <mn> on either Firefox or Chrome. Here is a codepen demonstrating that:

https://codepen.io/dginev/pen/QWzVZNj

So I am opening an issue to ask:

• should word-break: break-all; be used in such situations?
• if not, what is a good mechanism to achieve reflow, specifically when the plain-text content of a token element exceeds the page width.

Context: In a recent discussion of a web resource (namely computational discovery on jupyter ), I encountered an example which deposits an <mn> with 694 binary digits.

Start with the linked CodePen reproduction and the MathML token-element behavior described in this issue, focusing on the overflowing example. Compare the observed browser behavior with the relevant MathML Core layout and CSS expectations; done means documenting or agreeing on a clear reflow strategy for oversized token text.