I guess the problem with subsidised routes is pretty much that those who pay the piper tell what tune has to beplayed. So usually they expect to have an aircraft based that operates to the most desirable schedule etc. Not sure if Air France would be that co-operative. As the potential customers would probably mostly have rather deep pockets, maybe some interlining would be sufficient. Works quite okay over here with some of the subsidised route which serve MUC; they are all not operated by the Lufthansa group, but by independent regional carriers that are quite willing to base an aircraft if the subsidy is big enough.
One other thought - if Air France isn't interested, couldn't Atlantic Express offer something subsidised ? Like JER 0630 - 0830 CDG 0900 - 0900 JER 0920 - 1020 STN 1050 - 1150 JER 1540 - 1640 STN 1710 - 1810 JER 1830 - 2030 CDG 2100 - JER 2100.
As we just at it - how about the ZRH link ?