Yes you could fill the tank with water and pressurize it some how, in most cases it would only require 1 psi or less of additional pressure. A simpler approach would be to just use a fluid with a density 1.5x that of seawater. With a large storage tank and pump you could reuse the fluid indefinitely.

pardon my ignorance, could you also blast each pane with a pre determined PSI as well?

I would think you could easily call your tanks the safest glass on the market if you did have some kind of testing process...

And we all know aquarists, for the most part, love reasons to spend more money on better tings.

I wouldn't see any point in that as failure typically only occurs as a result of defects in the seams during tank assembly. Glass is glass for the most part and failures don't occur from defective glass unless it was chipped during cutting or assembly but that would also be captured from a standard hydrotest.

but wouldn't blasting the glass put pressure on the seams?

meaning blasting the assembled tank, from the inside, with a predetermined PSI?

If you pressurized the whole assembled tank then yes but pressurizing with air alone would not be advisable. Water or fluid is used because it's incompressible, if a leak forms during testing it basically just leaks while using air or gas will expand and potentially cause more damage if a leak forms. Basically without fluid you could be building a bomb which is not something you want in your shop. Also this test wouldn't be something you would do on normal or average tanks, really just large/specialty custom tanks that would have a large investment behind them. The cost of doing such a test would be high as the builder would probably spend more on producing a stronger tank to ensure it passes a hydrotest. For example spending more time on sealing (stages), machining all edges including non- exposed and/or using thicker glass.

Manufacturer
 

Note the Manufacturers post regarding the tank belonging to someone prior. A tank that size and............................. No one knows what stress the tank went through prior to the second owner.

I think some people need to realize that manufactures aren't liable for this type of thing. They may offer a warranty but like all warranties they are limited and up the discretion of the manufacture, anyone that's actually read the fine print in a warranty agreement would know they mean relatively nothing. While a good builder will stand behind their work and would offer something in cases like this there's often more to these kinds of stories and even how you approach the builder or manufacture is critical. Also with such a large amount of additional damage no manufacture with a lawyer on speed dial will ever admit fault as it could force their hand to cover additional damages which I would argue is in no way their responsibility. In the end best case they should or would cover the tank by either replacing it or fixing it but after such an incident who would honestly want that... So really this is a shitty deal type of case, live and learn, move on with your life.

With no design standards applied to aquariums its up to consumers to specify design requirements. This whole going big as possible on a budget is really just a recipe for disaster. You want hundreds of gallons of salt water in your house? Be prepared, this type of disaster probably occurs a lot more often than you may realize and in the end the consequences are your own.