If anecdotal evidence is helpful, I'm using ZFS with CGD (ZFS on GPT on CGD on GPT...) without problems and I know at least one other developer is doing the same.
- cgd + zfs Pouya Tafti
- Re: cgd + zfs nia
- Re: cgd + zfs Brad Spencer
- Re: cgd + zfs Pouya Tafti
- Re: cgd + zfs Pouya Tafti
- Re: cgd + zfs Brad Spencer
- Re: cgd + zfs Greg Troxel
- Re: cgd + zfs Brad Spencer
- Re: cgd + zfs Pouya Tafti
- Re: cgd + zfs David Brownlee
- Re: cgd + zfs Michael van Elst
- Re: cgd + zfs Pouya Tafti