I brewed around the same time with the same strain, mine is also ropey. Tasting fantastic though! Can't wait to bottle half and put the other on some fruit.
I was also considering using sacch along with built up dregs and then read it was 100% brett fermentation so decided against it. When building up the dregs you are essentially making starter after starter. My fermentation took off around 18 hours after pitch.
I also built up dregs from Sanctification to make a clone of this beer. I pitched the Brett/bacteria and it took about 6 weeks before it stalled out around 1.011. I bottled to 3.5 volumes in thick Belgian bottles. I think they carbed higher than that making me think the Brett wasn't completely...
I'm looking for Serenity and am willing to expand trade. I have access to Pipeworks, Half Acre, Revolution, 3 Floyds, etc. PM me if interested. Cheers!