Most relevant part to us I think appears in §3.2.2:
[...] The General Plan also proposes a bikeway along SR-35 from Sneath Lane to the San Andreas Trail entrance as a part of the 2030 Plan. Currently the San Andreas Trail is accessible from the San Bruno Avenue West and SR-35 intersection. The Trail provides a designated path for non-motorized methods of transportation south from San Bruno Avenue West. The proposed bikeway would serve an existing gap in designated bicycle routes from Sneath Lane to San Bruno Avenue West. Discussions with the City of San Bruno are recommended during project design in case additional SR-35 lane(s) are incompatible with bicycle traffic on SR-35, particularly between Sneath Lane and San Bruno Avenue West.
If there are temporary closures during construction, can re-route between Sneath to San Bruno Avenue via Earl/Glenview. But past that, the only viable alternative route is the S.A.T. itself, since there's no other way to cross 280 that doesn't go all the way down the hill to San Bruno.
I don't feel strongly one way or the other about this proposal, *unless* the proposal would advance removing bicycle access from that section of 35/280. The S.A.T. can close at the whims of SFPUC, after all.