Yeah I would not trust just superglue to hold my rocks together.I had MR rock both superglued in spots, and Emarco. Over a couple years the super glue pretty much failed at every location, accept the spots where I drilled the rock and put acrylic rod in it. I had arches last 4 years that were Emarco only, no acrylic. I say for year as that is when the system was taken down.
Large volumes of SG can be obtained from the same company BAR used to sell... https://bsi-inc.com/ and it's in California