We've been discussing ways of implementing things found in the F3 menu and commands in a vanilla way.
I had a thought earlier about perhaps, instead of a !nearestpost command/calc, perhaps each post could have a lodestone underneath it - where the post connects to the base. Then perhaps shift right clicking with a compass or some other such action could attune a compass to the nearest post's lodestone?
Just a thought, feel free to expand/pass over :)
~Mell