Quoted from MikeVarney:
I've been seeing alot of mention about the benefit of taking black paint and painting around all the inserts. Would you guys recommend that as well? Seems like that would make any slight misalignments look better.
We ended up doing black outlines around a few inserts, but doing so around all inserts would be overkill.
Again, as others have said, play around with the fit - there will probably be a few areas where things don't line up perfectly, so you want to split the difference as much as possible and black around the occasional misalignments. On mine, the one slight area of bare wood showing is under the "extra ball" insert because I had to sacrifice a bit of ground there to make stuff line up properly in the lower section of the play field...and blacking around the edge of that insert would have obscured the "ball" lettering. Had I preemptively blacked every insert edge, the "ball" wouldn't show on the final run.
By the way, I'm really grateful to have had a second pair of hands to help with the alignment. I stood at the top and my buddy was at the bottom so we just took turns gently pulling each way until we achieved the best-case-scenario. It wasn't totally necessary, but it made the process easier.