The problem is that the 787 IS coming, and IS going to be doing up to ULH, and an FRMS is going to be required because it can't just be grandfathered into existing rules given the possible flight times on a routine basis.
This was recently put out by AIPA
B787 Perth to London Operations
With B787 crew rest arrangements in place, we also reached agreement on the PER-LHR sector.
EBA9 clause RM20.3 covers operations to a maximum of 16:30 hours flight time or an 18:00 hour duty period. As the PER-LHR sector is planned at 17:20 and 18:50 respectively, this requires a specific agreement.
Such agreements are made on a city pair basis so it also covers LHR-PER, even though it has a planned flight time of less than 16:30 hours. This follows the same process that led to agreements in the past for DFW operations on the B744 and A380.
The agreement provides for:
PER-LHR max flight time 18:20 hours
LHR-PER max flight time 17:40 hours
Avoiding an FRMS is going be a tricky job given the proposed maximum flight time. Will CASA simply promulgate a city pair specific FRMS, but say to everyone else "business as usual" non-FRMS arrangement? That's going to be a very difficult fence to sit on for CASA. How will it explain it?
I see it as a binary choice. You justify an FRMS as "evidence based" rules system, yet that shouldn't apply to the rest of your Flight & Duty rules where it may actually cost money.