Thanks for the informative replies.
I lack the french language so can not comment on that one.
AFAIK BUSS activation comes with increased workload (e.g. ALT LAW and manual outflow valve control)
From the report :
After using the BUSS on simulator, the experts have realized that
- the flying request a lot of attention
- the flying is tricky during a config change
- the system is not adapted for a long flight