A none inflatable airlock that will fit in the Dragon's trunk would need designing from scratch.
As for the suitport technology demonstration - they are probably the part of NASA paying for the flight.
Non sequitur. Any airlock supporting suitport technology " would need designing from scratch." BEAM does not provide any advantage.
Again, another non sequitur. There are no new suits, therefore no suitport technology demonstration and hence no part of NASA paying for anything.
This isn't happening in the next 5 years and so it is senseless talking about how it could happen with present day groups and hardware.