I don't do a lot of throttle blipping, but do run up and down the complete RPM range (not lugging nor continually bouncing off the limiter) and use all the available gearing during my rides on our lovely foothills and Appalachian Mountain roads and with just over 6,000 miles the oil level stayed midway in the sight glass, she shifted wonderfully and just kept running better and better. At the 6K service all valves were in spec, but the shop did a great "anal retentive" adjustment to put them all as reasonably close as can be.
With the separate unit construction I can't think of anything you nor any other "test rider" could do via blipping or otherwise that would cause a pressurized transmission that was blowing lubricant out the relief valve. Not that something like a seal couldn't fail and easily be replaced, but I go with KISS for most "new" issues and always, always check what work was recently done. Odd that a good valve with so few miles would suddenly go bad, but easily checked, re torqued with a new seal or replaced if it did fail or maybe someone just had an aw-shit and some oil went where not intended and it wasn't completely cleaned and the ride home with heat and wind allowed it to come out of the nooks and crannies it was hiding in?
This isn't your situation, but I remember on the Triumph forums years ago that new owners would have worries their new bikes were leaking just like the "old" new Triumphs did, but it always turned out that at the time Triumph was shipping bikes with a cosmoline like protectant that was hard to get rid of from all the hiding places until it had a few more washes than what they received during dealer prep. They would ride in the rain or wash their bike and come out to find little puddles of the residue and it was a quick little kick in the nuts until they could confirm it was of no concern.
Anyway, hope they do what's right and get you in sooner than later!