HTupolev

It's really hard to give a simple answer because it depends on all parts of the system. Inner tubes and bead hooks both increase the safety margin against blow-offs, although of course this can be represented in a tire's specifications. On any random selection of properly-built rim and tire, it's likely that it will tolerate pressures far above rating without blowing off, but this doesn't mean that you should do so: tire blow-off is an extremely dangerous failure mode, so a margin of safety is built into the typical case to account for variances in rim and tire design and manufacture, and in pressure gauge accuracy, all of which can be all over the place. In other words, a major reason that blow-offs from over-pressure aren't common is that a large majority of cyclists respect the manufacturer maximum pressure specifications.

In the current market, I'd argue that it's incredibly dangerous to be telling people that it's probably fine to go 50% percent above max ratings, because many current products (especially in the tubeless) use significantly narrower margins than that for design certification and/or manufacturing test. I know multiple riders, on different types of tires from different manufacturers, who experienced blow-offs while running tires at just barely above their nominal maximum PSI. One of them took significant injuries from the crash and was off the bike for a while as a result.