The idea was to write my own code for it from scratch using the same notetag format as yours has, which was similar enough that I felt I should run it past you even if I'm not copying anything you actually wrote, but I'm just going to build on the official BattleVoiceMZ plugin instead. Thanks!
The main thing the client wanted was a plugin that does what yours does but that works in MZ, and has some more options for events that trigger SEs.