Update 52 reset my containers

So I’ve been asked to continue this here…
When containers arrived I turned it on, played with it, adding some of my own containers and copying loads of tabs into them… nice looks like a replacement for tab groups, then Firefox update 52 arrived yesterday (Ubuntu 64) and bam, containers back to default, the only thing left was the work container, which I’d just changed the colour of, the three new ones, gone.
While I understand these are test pilot things, I thought you’d at least test that.
I assume there’s no way to get them back apart from going through my history, another day lost…

Also mentioned here: http://bit.ly/2mJXxgN