They'd probably be cold to the whole idea. Opening up the HV station as a spur off the R3 makes sense. Its a turnout or two, s.e.p.t.a. could store trains there overnight, and could provide some additional service to the stations between there and Noble, and if its bigger than Bethayres, maybe even close/consolidate that into a single stop.
Is there really a need for train service north of Bethayres though? SEPTA says no one will ride the train, and an R8 will just siphon off riders. Why not do more buses that feed the other lines? Or build more parking? Armchair-ing aside (and they're all great comments), why not a mega-station in Warminster? Or a bigger Trevose? Does anyone in Newtown even go to Philly?