I think that posting bug reports per se on tex.sx is generally a bad idea, independent of the question of whether they fit into the Q/A format of the site. The reason is that since the site is intended to be a long term repository, there's a very good chance that bug report posts wouldn't get updated when the bugs are actually fixed. (I'm not saying that you wouldn't update, but that in general it's a likely occurrence if the practice of using the site to advertise bugs becomes institutionalized.)
Of course, if users' questions give rise to a bug report, then a bug report is obviously acceptable as part of an answer to a question (although I always try to be sure to update such answers if I give them if the bug subsequently gets fixed.)
Even on comp.tex.tex (and I suspect also on texhax) there seems to be some general consensus that bug reports are best reported directly to the package author(s) rather than to those forums directly.
The only time such reports make sense is when the package author has been unresponsive, or the bug has persisted for a long time (which in your specific case doesn't seem to be true.) But even in these cases I don't think that preemptive reports are necessary here. If the bug is noticeable to enough users, the chances are that it will elicit a question or two independently, in which case the bug can be reported in the normal course of answering the question.