Does it matter if other people put inlays in another makers' cue? Would it hurt or help the cue?
Depends on the situation imo. Here's a few examples, maybe at opposite ends of the spectrum.
Gus with inlays by Schon or Phillippi.......drastically hurts value imo
Joss production cue with Gus inlays............greatly accentuates value
Ok. Here is a scenario. Lets say it is a Hercek 4 pointer. Then joe Shmo down the block decides to have his local cue guy put inlays in it. They screw up after the first one. Then on down the road, another person tries to fix it and replaces the first persons inlay and adds a few more, as far as I know, none are credible.