Yeah, you tend to have that high strength endurance so you can lift a lot closer to your 1Rm for reps than the average lifter. So it is likely a little skewed.
I know, every time I keep seeing them I think wonder what his progress would be without all the joker sets taxing his CNS regularly.
It's okay, it is your cookies you are stealing, it ain't hurting anyone else's progress, and it seems to increase your enjoyment. So as long as you are aware of the trade off, and are enjoying the process it isn't an issue.