Possibly, but it's about 10-15% by volume per event, and I sample after every event for now. I try to take samples after the make-up oil has been through several drive cycles on the track, never right after adding it. I don't need to add make up oil on the street. Plus, what I am interested in is the trends not the specific values. So, as long as I maintain the same sampling methodology I think it should be comparable between oil samples.
I would argue that doing an UOA on this engine is much more vital than doing it on a street driven engine with long OCIs. In the latter case, as long as you change the oil often enough and use close enough to the OEM viscosity you'll probably be fine. In my case, if I use the wrong oil I could lose an engine in a single track event. Plus, the wear trends can tell me when it's time to start thinking about a rebuild. I doubt most street engines are rebuilt, but just replaced.