Acting for Two: In Spamilton two songs have the female lead (Nora Schell on the Broadway Cast Album) sing for three:
"Look Around (The Schuyler Puppets)" has the female lead play "Renee Elise," and use puppets to portray "Phillipa Soo" and "Jasmine," changing her voice to fit the sister she's singing.
"Lin-Manuel & J-Lo, Beyonce and Gloria Estefan" has the female lead play the Jennifer Lopez, Beyonce Knowles and Gloria Estefan, as each diva tries to get a song from Lin-Manuel. The female lead also sings in the style of the diva she's portraying at the time.
Approval of God: Lin-Manuel Miranda has been to see Spamilton TWICE, and said "I laughed my brains out!" (This was used on the Broadway Cast Album.) He also gave props to Dan Rosales, who plays his fictional version, "Lin-Manuel as Hamilton." Lin even gave the cast tickets for Hamilton as well as a few suggestions when the show was in previews. Dan also took a picture with Lin-Manuel while in character for his Twitter.
Shallow Parody: New York Magazine's review of Comes Out Swinging noted that the show occasionally slips into this, such as getting Santino Fontana's race wrong in the Cinderella parody by claiming he's Latino. The critic noted that it's not a good idea to go shallow when the only people likely to go see a parody of stage musicals are ones who love stage musicals to begin with and are thus more likely to notice when you goof up. The 2014 London edition calling Charlie and the Chocolate Factory a "pale Matildaimitation" isn't much better (Charlie was well into development when Matilda premiered).
Suspiciously Similar Song: Alessandrini has occasionally written ersatz versions of songs he couldn't get permission to parody.
"And although we're a low, Hasty Pudding show, the kiddies cheer on cue... Families come, if they're dumb, but then out they go, when our fuzzy people screw! Don't expect The Muppets, these are horny puppets, rated X on Avenue Q!"