So, for Inanimate Insanity S4E1's first song, Welcome to the OSC!, Suitcase has a separate voice actor for when she sings.
And it's possibly due to Suitcase being Sam Thornbury's hardest character to voice act.

This somehow gave me an idea.

Remember when I decided John Archer II will be MePhone4's alternative voice actor in this game after watching S1RE1?
I'll be doing the same with Suitcase. Austin Nebbia will be Suitcase's alternative voice actor.

However, I decided to change the way toggling between original and alternative voices works for MePhone4 and Suitcase.
You'll have to go to the Account Menu, enter the Wardrobe section, and when MePhone4 or Suitcase is selected, press Alt to toggle between the original and alternative voice. (You will be able to do the same thing in the character select menu)

Suitcase's alternative voice will be unlocked by default in the demo, but will require speedrunning 2-3 in the full version.