I think that there is no consistent approach. Like you, I researched it, and came up with the same options - leave it alone, epoxy, Interprotect, bottom paint, etc. And when I wandered around the boatyard, I saw all the variants described.
FWIW my strut is Aluminium, and has bottom coat painted on - which never lasts.
I wonder what could be causing the corrosion; bronze is normally pretty durable. It is bonded to the rest of the grounding? Could you have some stray current?
Sorry not to be more help :-(