Theoretically no, it's not worth swapping to Hemo from your current build (assuming my Shadowcraft optimization isn't terrible). I also doubt that switching to Backstab will be even a noticeable difference unless your kill time favors Subtlety significantly.
My advice would be stick with what your doing right now, particularly if you're referring to Malkorok & Nazgrim HC which can have decent cleave potential. That, and it will also save you a lot of effort reforging and gemming several times a week.
I did some checking a while ago for a "general" checkup on the loss of using a 2.6 hemo build in place of Backstab; the loss was high enough to be a "no" for any serious progression, but if you're fooling around, it wasn't 20%+ (if you want to hunt through some of my old posts this was... a couple of weeks ago? A month maybe? iirc it was in the 9% area).
Take a sub profile in Shadowcraft. Change combo builder to hemo. Change mainhand (and off, based on your post) to 2.6 weapons. Go to custom stat weights and set mastery above the rest, then reforge with custom weights.