They are now saying in their (web site) advertising what many had already figured out by just trying it out: The Sportsman Formula works as a tubeless sealant that never dries out.
Also I specifically called them and asked about using it as a tubeless sealant on my 60 psi Maxxis Aggressor tires that went on about what I guess is now 2 weeks ago. I called them out on the high pressure issue and they said a) they are not yet recommending Flatout on other-than-fat tubeless tires because they haven't completed testing yet and b) "air pressure is not an issue". What they mean by that exactly we will see. But so far my tires are holding 60 psi perfectly. Before sealant went in, they deflated in about a day. So its able to do *something*. No bubbling thru anywhere when it went in. Rims are DT FR560's with DT tape and Muc-Off valves. The bike is mostly on urban streets so its only a matter of time before we see whether it seals a flat at the higher pressure.