Older mechanics experiences

Hello so I've been told back then when a sbc started having issues of a flat cam mechanics would replace it and be on there way. I wanna know if anyone's done that before and had no long term issues. Would super small prices of metal be able to pass through and not be a big worry for the new cam break in? There would have to be some left over if the cam was going flat over time. The oil filter would catch the big stuff but there's gotta be atleast some super small pieces in there that can go through the passages and not hurt anything.thank you