the frames are nothing but nylon with glass added, so abrasives will embed if trapped in areas, although not much harm on stamped trigger bars, areas where things pivot could be a different matter...I'm quite sure you are being truthful about being completely satisfied and no apparent harm happening, but normally it's best to remove parts to polish them so polishing compound doesn't hide places and then migrate, accelerating wear, which i am sure you already know....really only saying all this for the newbies' benefit, as if i don't, and didn't wrangle a statement from you about removing stuff with a q-tip or something, sure enough somebody would go overboard on application and/or do a totally inadequate cleanup and regret the "smithing" later as abrasive sludge did its work...i'm quite interested in hearing how your smoothing did so much without needing to do much else, and thanks for the post