A local group here did Musical of Musicals six or seven years ago, just the cast of four (which I'm presuming is what it's written for?), one of whom also doubled on playing the piano (likewise?). That cast understood every reference and joke they were making, the staging was clever and fast-paced, and the small venue was perfect for it. I do remember thinking a few of the bits or songs could have been written even shorter, but it was a charming evening.
Based on what I've been reading, I can already imagine what this one's going to look like. I'll watch it or skip through it later with the expectations dial set to zero.