There are other fish tags in the ocean H2O
How about a mix?
FW* = 0.5・cW・v2・A・ρ
F<sub>W</sub><sup>*</sup> = 0.5・c<sub>W</sub>・v<sup>2</sup>・A・ρ
just kidding.
and the strikeout doesn’t work, not even in their guide. Markdown doesn’t have this tag originally, but the kramdown has it. Maybe it can be changed to that in the Discourse settings, I dunno.