[eluser]TheFuzzy0ne[/eluser]
Are you noticing any performance issues? Don't get me wrong, I'm all for performance optimisation, but if your tables are indexed correctly, I doubt that extra join will cost you much more than 0.01 seconds.
The main reason I'm so reluctant to change any code, is for the same reason that we frown upon editing files in the ./system directory. If you ever decide to upgrade the library (perhaps for a new fature, or a bug fix), it makes it quite difficult.
Perhaps database caching would give you the performance boost you're looking for?