"Use PD/4t" and "Add F/A in stresses" options doesn't have any impact on the anchor reactions magnitude.
Enabling or desabling these option modify only the stresses values. First option is suitable only for THIN WALL piping and regards the longitudinal pressure stress value. The second option includes the axial tensile/compression stress in the longitudinal code stress.
In conclusion, both options are used AFTER the pipe element forces&moments are computed.

Generally, the pipe element forces&moment assessment and the anchor reaction computation are not influenced by the piping design code.
As a general practice for the most projects I worked for, the loads acting on the anchors (i.e. equipment nozzles) are assessed/considered/checked for the basic loading cases (operating and sustained cases). Certainly, when specific checking methods are involved (such as WRC 107&297), then the thermal/expansion restraints are used for the corresponding stress evaluation.

Thank you for the reference article. I'll study it carefully.

Best regards,

Dorin