How and where to run gulp-bless for IE 9 support?

Thanks for responding @Twansparant. That’s close to what I originally had in an older Sage project I used.
Upon further investigation, there’s an issue with the most recent bless v4, now included with gulp-bless v3.1.0. https://github.com/BlessCSS/bless/issues/93
Since some function in Sage “injects” @charset, a typeError monkey wrench gets thrown, causing the bless process to fail.
In the interim, I’ve installed an older gulp-bless version.

While all compiles fine on gulp build, all is not well with gulp watch.

When running build, @import url('main-blessed1.css?z=1459617040469'); gets printed inside main.css, but while watching, @import url(…) never gets added back in even though bless is run.

[BS] Watching files...
[14:18:01] Starting 'wiredep'...
[14:18:01] Starting 'bless'...
[14:18:01] Finished 'wiredep' after 164 ms
[14:18:01] Starting 'styles'...
[14:18:01] Finished 'bless' after 126 ms
[BS] 1 file changed (main.css)
[14:18:09] Finished 'styles' after 8.21 s

Anyone else having this problem?