We forked from the version Mat Kovach provided, at least this is what we have been using. The difference from a first look at diff is that you changed it on 2nd of September, adding a check that subject contains no new lines (will be added in a few minutes) and a catch around the sending of queued items. We solved this a little bit differently, so not sure if we need to incorporate your code if the result is the same.
But maybe Tilmann is right, and we should go and take out the mail system confusion first. Which would lead me to the question, why do we have acs-mail and acs-mail-lite in the first place and what packages are using acs-mail. I mean, if we get rid of one of them my understanding is that we have to rename the mail-procs in each package, or am I utterly mistaken here (I admit, no look at the acs-mail code yet).