I\'ve tried several different approaches, including the one found here (which in turn led me to trying both of the top answers to this question), as well as using reflection
Figured it out eventually, it was because, from what I understand, TextViews that are set marquee need to be selected before they will actually start marqueeing. I updated my MarqueeToolbar class that I posted in the question, which can be found in this Gist: https://gist.github.com/InsanityOnABun/95c0757f2f527cc50e39