How big a tear? Patch on the inside is ime foolproof as long as it’s not too big, and can bodge a bigger hole but not that well. Worms are alright for an external fix but don’t make much sense once the tyre’s off, mushroom plugs are better but i reckon more suited for holes than tears…
Personally, I’ve sewn tyres up but I think it’s more hassle than it’s worth, I’ve used it on holiday etc but at home i’d replace.
So I guess what I’m saying is, I’ll patch it on the inside for preference and if the tear’s too big for that I won’t repair it at all usually. So no need for other methods.