Thank you, Dub.
For heaven sakes, just please make sure you have your keywords in the standard fields! You don't want to lose your data if you migrate DAMs or send pictures to someone who uses a different DAM.
Most DAMs (PM+ included) will return an asset if there's a matching string somewhere in a keyword. So, "... ,search term | another search term, ..." should return for a search on "term". In those cases, leaving the keywords "hierarchical" would work OK.
But some DAMs only match a whole keyword, which would be whatever is between the delimiters, usually commas. In such a case, you'd have to search for "search term | another search term" to return that asset. Which is probably not what you want. You never know how the next piece of software will behave.
And yeah, I don't use Lightroom anymore, either. That central database containing all the edits creeps me out. What's more, I just feel like PM > ON1 RAW (or Photoshop)> Photo Mechanic (Plus) gives me better functionality all the way through.