does anyone here new the convention for spacemacs on "bumping" PRs if they haven't been addressed? Mine has fallen off the front page (and doesn't seem to be being addressed), but I don't want to be obnixous about bringing attention to it.

I assume a gentle mention in the http://gitter.im spacemacs channel of your PR may help gain support. If people also add a "thumbs up" reaction to your PR on Github then that helps maintainers see which are the most popular PR's to include next