Rather than use the WAG method, and possibly besmirch the reputation of a dealership or independent without just cause, may I suggest just going forward with whatever brand of oil you like and check the level every 100 miles or so. If the bike is using oil at an excessive rate, it should become obvious rather quickly. And just because a compression test and leakdown test comes back good, and the plugs aren't black and oily, doesn't mean the engine can't be burning oil. For instance, valve stem oil seals haven't been terribly reliable at H-D and will allow oil to pass without affecting compression or leakdown testing. And these engines run so hot that you won't necessarily see black oily deposits on the plugs like we did in the old days, at least until the consumption rate gets much worse than 2000 miles per quart (6000 miles, roughly 3 quarts unaccounted for).
Even though most vehicles these days don't require constant verification of the motor oil level (I haven't owned a car in decades that needed oil added between changes), it's still a good idea with a Harley to get into the habit of checking it on a regular basis. And in case you wonder why the 1 quart the indy drained out was so nasty looking and thick, that's what severe overheating does to motor oil. With only 1 quart or so circulating in an engine that normally has 3.5 to 4.0 quarts, the oil will get much hotter. Even the best synthetics can't handle severe overheating for extended periods of time.
Jerry