I've added this to my project (which primarily uses NVL mode), and it seemingly works fine- except adjusting the speech_pause_comma and speech_pause_period variables doesn't affect the pause speed at all, even when I use absurdly large numbers that would surely cause a noticeable difference. This happens with both version A and B. HOWEVER!! When i change the pause speed from the preferences menu using the code snippet provided, it DOES affect the speed. wtf??
I'm saving my files and completely restarting renpy between changes and everything. My writer was the first to report the bug so we've both experienced it between 3 different computers.