So, let me preface this with I do not and will not be planning to run any tire sealant in my TT tires. I do not believe tire sealant will prevent a blow out as tire sealant is designed to seal small holes, like a nail/screw that is leaking. A guess here, but trailer tire blow outs seem more caused by a catastrophic tire failure, something tire sealant won't help with.
Having said all of that, the tire sealant the OP has linked is not the same tire sealant most are going on about. Stuff like fix-a-flat and Slime are horrible products and not the same as the newer formulas. The newer formulas use a suspension liquid to carry "large" particles, if you will, via a quick burst of air releasing, where that particle helps plug the leak. That suspension liquid is a lot lighter and easier flowing than fix-a-flat/Slime.
Tire sealant is an extremely common practice now for tubeless tires on mountain bikes that are actually used for MTBing. I have been using it for years with no adverse issues. Yes, my MTB hubs and rims are aluminum. The tire sealant works incredibly well unless you slash a sidewall. And for those saying, but yeah, a flat on a MTB is not the same and is not going to cause a big issue. To you I'd say you are 100% wrong. With the types of trails I ride and the way I ride, I could seriously injure myself or worse from a tire/wheel problem. MTB is a passion for me and to support that comment, my two most ridden MTBs have cost me upwards of $10k US dollars. I ride those a lot.
I have liked my tubeless MTB tires with sealant so much, I have added an ATV recommended tire sealant to my front Yamaha Grizzly ATV tires. Those ATV tires are mounted on aluminum wheels. So far no issues but I've only ran that tire sealant on the ATV for about 1 1/2 years so far. Again, the way and places I ride (CO high country, Moab), I would not want a tire issue on my ATV either. I have not added the sealant to the ATV's rear tires, yet, as the good sealants are not cheap.