Jack, it's really not correct to say that Bohmian beables are 'obviously required'.
JS: I think it is correct. It's a matter of opinion.
RK: I give an alternative account in my book
that allows for the emergence of the 'classical macroscopic world'.
JS: I think that you have replaced one mystery with another. This word "possibility" is "real". I see no essential physical difference between how you use "possibility" and how Bohmians use "Q". Also the Bohmian beable is Wheeler's IT and Bohm's Q is Wheeler's BIT in
IT FROM BIT.
RK:Others give different interpretations that I don't agree
with for various reason (e.g. MWI because it doesn't provide a good physical reason for Born Rule, and splitting of worlds via decoherence is ultimately observer-dependent), but those don't rely on beables either.
JS: Valentini has explained the origin of the Born rule as a contingency in terms of the statistical mechanics of beables. Now Valentini may have erred in his recent stability claims. But even if we fall back on what he calls de Broglie dynamics instead of Bohm dynamics we still have the Born rule as a contingency and not an absolute truth.
RK:You may prefer the Bohmian account, but that's certainly not a basis for saying that it's 'obviously required'.
JS: Show me how you get the basic beable which is Maxwell-Cartan 2-form F for the electromagnetic field.
F = dA
dF = 0
d*F = *J
d*J = 0