Please as you attempt your make it better project, for a reciprocating engine, Clean oil is best but Dirty oil is always better than no oil. o not attempt to put a very fine filter in series with the Lube Oil Pump, because these filters will usually plug quickly then you either wind up with no oil(if there is no bypass) or dirty oil (if there is a bypass.
It sounds like you have a very high dirt load coming into the engine. If this is the case, a three prong strategy is recommended.
First double up on the Air inlet filter. The engine manufacturer should be able to help here. Next leave the engine manufacturers filter alone as this will keep the boulders from getting into the bearings. Next use one of these self powered centrifuges to take out the 20-50 micron particles (This unit will take 10% of the flow, and return it to the sump.) Next install a very large depth filter in Parallel with the centrifuge to remove the 3-20 Micron Fine material. This strategy should work well to keep you at NAS Class 4 or better.
Change the all filters and clean the Centrifuge (Liner Papers are available) Monthly, and test the oil monthly to keep the oil in good condition. If you maintain NAS2 for three months back off to a 2 Month Schedule. Also Please top up regardless of what happens at the Manufacturers regular schedule. Also weigh the sludge every time you clean it and put the KG in the engine log book.
Let me know what happens