UPDATE: the change is now live. If you pull an Enhancement within your tier, it will not count towards the guaranteed pull. An example is listed in the post.
We're currently testing a change that will make Enhancements no longer count towards guaranteed pulls. This will be released as a server update when it's ready for primetime.
How will this work? If, for instance, your deck is in Epic tier and you pull an Epic Enhancement, that Enhancement will not count towards the Epic Superstar, Legend, Diva, or Support card that's inevitably coming your way. Rare (and above) Enhancements will still reset the board when this change is live.
To put it another way: if you pull an Enhancement within your tier, it won't have an effect on the counter.
You can read more about resets and S2 mechanics in this thread on the 2K forums.