With a higher flow pump oil pressure will be higher at low speeds, but once up to the pressure regulator setting excess oil is by passed. No increase in flow though the crank, so no worries over sludge trap being disturbed. Whether there could be more problem of the extra oil being breathed out I don't know. But the SRM pump does appear a lot more efficient at low speeds which may be a worthwhile improvement.
Last time I monitored pressure (with a good standard pump) it reached 60 psi at little more than a fast idle even with the oil warm (not really hot), so no problem there.
I now have the earlier type WDB40 filter fitted and it appears to do a fine job. Found it easy to wash through the element for re-use which fits well with BSA maintenance tradition. Not burning oil now with new rings fitted, and its staying clean.
Can't see why you would want to take rocker feed off before the filter Steve ????. Filter pressure drop will then increase oil flow to the rockers which could lead to oil burning problems. 50 grade oil may not be a good idea with an external filter. When cold pressure drop could be excessive, at minimum leading to captured debris being reinjected into the flow, worse outright rupture
. Not nice. (Have just read an article on Dynamic Filter Efficiency which talks about pressure effects on filter elements, and worried myself a bit.)
So to work
or is it more
Mike