Okay so people who are she/her use "Ms." as a title like "Ms. Pac Man", and people who are they/them use "Mx.", and so it has just occurred to me that people who are she/they could use "Msx." which rules
@mcc
By extrapolation, we can infer that "Mrs." signifies he/her, and "Mssr." signifies she/her (accusative)/him(dative)
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