I actually installed it as a custom init on mine without the aid of preinit. I looked through the preinit documentation and saw my mistake. Preinit doesn't wait for 'M' scripts to execute before launching the player. 'B' scripts are for that. Rename the file M10tts to B10tts and it should work. I'd reccomend testing the script from the command line before rebooting to make sure it works, because if something is wrong with a 'B' script it would render it unbootable and force you reflash the kernel. Make sure the script has permissions and just type "B10tts" and it should speak the time and return to the bash prompt. If it works then you're safe to reboot.

I have posted an updated version so all downloads from now on will have the file as a 'B' script.