Iām not OP, but the startup ethos of the last few decades has been to move fast and break things, fake it til you make it, and generally operate on the bleeding edge to deliver incredible products (and, occasionally non-credible, cough Theranos).
My concern would be that the team would cut safety corners until the probability of success just barely rises above some threshold, rather than engineering everything to have as low a risk as is feasible. Is 0-1atm easier than 1-infinity atm? Yes, but that just means you can cut more corners.
I buy it. OP's comment struck me as interesting, because the "above 1atm" value turns out to be about 300atm; designing a pressure vessel to sustain a 300atm pressure difference is much more challenging than one to withstand 1atm, which is the case for these balloons. If we assume relative cost cutting due to cultural concerns, then the analogy makes sense.