If it really isn’t technically possible (which I think you might be able to do in a Darwin VM), then maybe this approach isn’t a good idea.
Tomorrow Apple might decide it is safe to chroot with SIP enabled (I actually do not understand why they restrict it, chroot is a tool to increase security). Does that suddenly convert bad design into a good design? But this is exactly the same design.
Does this current design require disabling SIP? Then I don’t think it is worth my effort to use (for my use case). If Apple changes the system in the future, my opinion might change.
But a design cannot be judged as good or bad outside of the context for which it was designed.
If you feel this is a better way to tackle the problem, then talk to Apple about it.
That's a technical limitation.