Let me add some amateur thoughts. As the track is single through Kentsford and Leigh Wood at present, any or either loop there would not need to be "heritage". During none-heritage operation, intermediate heritage boxes switched out, signals left pulled off in both directions, and a single platform in use. Leaving, purely, the issue of the level crossing operation to be overcome. Williton's Station Road is only about 40 metres to the north of the A39 bridge BUT that may be an issue for access by pedestians and cycles if it was to be shut permanently across the road. Blue Anchor much more of a problem if you want to retain heritage - a very long way round if you close the crossing, and not practical to build a new half barrier crossing 100 yards or so to the west. Don't see National Rail gates operated by train manager finding much favour, nor "Stop and Proceed" which in any case would destroy the gates.
I don't think there's much "amateur" about these thoughts
Plans existed for the remote operation of the loops at Kentsford and Leigh Wood 40+ years ago. If they've not rotted, I'm sure they can be dusted off. Either using motor-worked semaphores or searchlight signals wouldn't be objectionable. Either long/short section token working or do away with tokens in favour of a more modern single-line control, which would perhaps be a bit more challenging for heritage aficionados. very do-able, given the will and the lolly.
When we took-over the line and in the process of setting up the original LR(T)O, in 1974 or thereabouts, the non public-road status of the level crossing at Williton got overlooked somehow. There were signs up at the crossing informing of this status, but the very clever people in charge ignored history.
BR▸ (and presumably it's predecessors) had chained-up the gates one day per year to prevent a right of way coming into being. By the time we got to the actual re-opening at Williton in August 1976, it was too late. No correction of the oversight could be countenanced by
HMRI▸ . The gates would normally be left open for road traffic and closed only for passage of trains. The gates had, in big-railway days been left closed across the road, for road users to operate at times when they were unlocked from the 'box. Closing them for a train became the responsibility of the railway. Williton might need to be open as a cossing loop in even a sparse winter service, though
Blue Anchor is not easy to "solve". The
LC▸ is not well situated from a highways point of view, approached from the northern side by a sharp left blind bend in the road. I don't think here's much chance of any type of remotely supervised (other than perhaps
CCTV▸ ) crossing being permitted here. "Upgrading" to lights and barriers would destroy the heritage ambience. As would stop boards.
Plans existed back in the mid 1970s too for the switching out of Minehead 'box and auto operation of arriving and departing trains. That was before Seaward Way LC was a thing. Now that the LC is CCTV supervised, perhaps there's potential fo this to be controlled from elsewhere - Blue Anchor, perhaps?