It is to inform you that the issue which you are facing is actually not a bug in Aspose.Words. So, we have closed this issue (WORDSNET-22921) as ‘Not a Bug’.
You should either move the MathObject node outside the QUOTE field or surround it with double quotes.
I do not understand your solution, in the attached file I added quotes in several different ways, without being able to visualize the formulas after saving.