What part of what you quoted says that I believe any registration mandate is enforceable upon any citizen not enrolled in the militia?
That private individual citizens possess the right to arms without militia conditioning, for a myriad of lawful uses, does not extinguish the government's constitutionally legitimate powers over militia members performing their militia duty (see 5th Amendment for another example, grand jury rights suspended in lieu of UCMJ for crimes committed when in actual service.
What about the unorganized militia which is not connected with the regular militia and national guard?
unorganized militia = "citizen not enrolled in the militia" = "
private individual citizens [who] possess the right to arms without militia conditioning, for a myriad of lawful uses"
Which ≠
"militia members performing their militia duty" for whom Art I § 8, cl's 15 & 16 applies, by way of the Militia Act of 1792.
Militia laws are not enforceable upon private citizens and their personal arms . . . Only those citizens enrolled and the arm (singular) that they intend to muster with when called to perform militia duty.
Whatever rights a citizen possesses are qualified once he comes under the command of legitimate authority, in this case being in the militia.
Do you dispute that a citizen's 5th Amendment rights are conditioned upon one's militia enrollment and deployment status?