I thought these features were illegal...

[Sohum63]

Until they expire from the roster and is not renewed by the manufacturer (with their black mail payment to the state).

Or a part is changed. Chang from one type of metal to another for something as small as a slide catch and you are out, I believe.

[fmunk]

If it was on the roster when you bought it, which obviously it was, then yes.

Cheaper to pay the blackmail than to recertify with all the new wonderful requirements.

Yes, my comment was in context of sale from FFL to individual. As all should know (but don't), roster doesn't apply to PTP transfers via FFL.

Or a part is changed. ChangE from one type of metal to another for something as small as a slide catch and you are out, I believe.

Something like that, which supposedly is the case for all M&Ps (except Shield-CA).