Keeping in mind here that the basic problem is lack of a common display context for page/Postscript-origin apps like FM, and terminal/now-mobile contexts like HTML, there is no common model for second line indents. HTML5 "text-indent" only applies to the first line.
FM (or RH) semi-unsurprisingly implemented it as a borderless table, but then semi-shockingly put all the content in the first column, instead of putting the CAUTION in the 1st col, and the admonishment in the 2nd.
Musing: another other way to do this requires gaming both the left margin, and using negative text-indent. I can see why the devs might have decided, umm, no, don't think so, on that hack.
Anyway, that's yer problem. Not sure of a fix, other than deliberately implementing these admonishments as your own borderless tables in FM (which isn't then a simple para fmt apply op).
Frame-Above is what I used to use, and that might flow more cleanly to HTML.