On Tue, Oct 11, 2016 at 2:38 PM, Tomasz Kłoczko <kloczko.tomasz@gmail.com> wrote:
You have still 4th option:
- create from snapshots separated boot environment (BE)
- do upgrade in BE
- restart system from new BE

To be honest only tis method solves all hazards which are not listed in your 3 points and additionally you will have possibility to create packages without any post install/uninstall scripts which are biggest risk factor of ANY upgrades.

Thats fine, but first of all - those aren't my points - they are from the link I included regarding Project Tracer.  
My comment was directed at folks who were concerned about running dnf from a terminal within a DE - and
were interested in some type of risk mitigation now.  Your suggestion requires a bit more work.  As far as BTRFS
is concerned however, I believe that ship has sailed.  I used it for 4 years, but after the recent news regarding RAID 
I switched everything to XFS.