Higgs boson
Your understanding is correct.
LOC+G/S is used to fly the ILS signal, and there is no way to couple the LNAV or VNAV to FDs for an approach that is coded as ILS in the FMGS.
If the database legs finished at the GP intercept point, then a discontinuity followed until MAPt where the coding would resume, all the features we know should work as advertised in the FCOM regardless.
Yet it is coded there anyway.
Not a problem.