I make my own sealant. I work in the waterproofing industry so we have latex(high solids) and acrylics in 5gal pales just sitting around. I've never had a flat since moving to tubeless. I've pulled out small sticks and thorns but never flatted. I've even stabbed a tire 50 times with a ice pick and shot it with a pellet gun(sidewall), seals right up.
That being said, one day I will meet my match and either get a slash or pinch a hole to big to close. So this is what I carry in my SB now, a plug kit for tubeless mtn bikes that is small and about a quarter the weight of a tube. I also carry two large radial tire(for cars) patches with superglue for a boot if needed.
Slime tubes are for the birds. They weight like 80 pounds