It's stayed singles doubles because that's what most of the regulars want to play.
There are plenty of "regulars" interested in playing singles, we just need to find one that can show up to run league. If beginners want to play with pro's then league should be ran like it was in Columbia... Pro/Am. If it's random draw doubles every time, there is a good chance they might be paired with another beginner, defeating your purpose. Aside from tomorrow, June 1st, and June 22nd, I can be available to run it if no one else is going to step up. I would even consider running doubles once a month with the Pro/Am format.