As I think more about my post, I can rationalize that if there has been no filtration on the system since home completion in 1990, and little to no observation of water contaminates, I may not need consideration of a whole house filter.
My only intention is to provide one level of filteration before water hits the softening system to keep the resin tanks clean of any contaminates, or further limit contaminations from large size particles that the wound string filters would catch.
I suppose if anything does impact the resin tanks, backwashing should flush it out. I am probably beginning to over analyze this the more I think about it. Basically, filter before pressure tank or filter after pressure tank and before softener system. Softener system is original to the home and is in fine shape, doing well.
Kinetico guy had some difficulty disputing test results, even though his little crayola water testing kit is somewhat subjective in interpretation of color differences.