Comment by mkl

Even without technically changing font, there are more than you might expect: XxˣₓẊẋẌẍⅩⅹ⠭ꭖꭗꭘꭙ🄧⒳ⓍⓧＸｘ𝐗𝐱𝑋𝑥𝑿𝒙𝓍𝓧𝔁𝔛𝔵𝕏𝕩𝖃𝖝𝖷𝗑𝗫𝘅𝘟𝘹𝙓𝙭𝚇𝚡🅇🅧🆇

https://unicode-table.com/en/blocks/mathematical-alphanumeri...