This is a question alot of people working at Boeing and Space-X get paid handsomely to answer on a near-daily basis. I’ve worked on both sides of the government/contractor fence on more than one space program, so I have a basic familiarity with how they operate. Space is a realm with alot of unknowns. Like my flair for the obvious?
We can be absolutely certain the root causes for any spacesuit incompatibility are corporate competition and proprietary exclusivity supporting nothing but profit motive. Has nothing to do with crew safety, mission effectiveness, or performance/reliability concerns. There’s probably more than a few executives at these companies that need to be retiring or looking for new jobs. JMHO.
To make things even more complicated, the Crew Dragon currently at the ISS is already carrying four crew members, and while it was initially designed to hold seven, it’s been reconfigured to accommodate just four. Even if NASA could get compatible suits for Williams and Wilmore, the Crew Dragon doesn’t have the necessary setup to support them.
Called it. Space-X using USB-C while Boeing still on the old style connectors? Maybe 1 or 2 universal-fit emergency spares stored somewhere? How about an empty-seat rider schedule? Lots of things to toss around…
Why isn’t interoperability a key specification in these contracts? I’d still like to know exactly who signed off on the suit interfaces from both companies and NASA. They got some ‘splainin to do.