boost 1.87 does not have bjam options 'numa' or 'context-impl'

[bgemmill]

When compiling boost with fiber, version 1.86 would take the bjam options numa=on and context-impl=ucontext and build appropriately.

With boost 1.87, I see:
error: Invalid property '<numa>on': unknown feature 'numa'.
and
error: unknown feature "<context-impl>"

The documentation still mentions that this is the way to pass these options in; has the method changed?