They could, but it might be considered risky or maybe outright not possible with the current design, since the EVA hoses would be different from the ones normal

They could, but it might be considered risky or maybe outright not possible with the current design, since the EVA hoses would be different from the ones normally used within the capsule. It isn't that the problems can't be solved, just that NASA doesn't think it's worth working on just yet. Tbh I wouldn't be surprised if they're hoping to get government funding so that they can be the controlling party (vs a private mission, where, ultimately, they have to compromise with the specific things Isaacman would be willing to fund and within the timeline within which he's willing to keep funding).