As far as not withdrawing their support it seems each was excommunicating the other. Please consider:
”Most significantly, Patriarch Photios called the addition of the Filioque in the West a blasphemy, and presented a substantial theological argument against the view of the Trinity which he believed it depicted.”
If they didn’t withdraw their support they sure had a nasty food fight. I doubt if you'll get an Eastern Orthodox to agree to the Nicene Creed as published by the RCC. (At least that was the case on this website.)
To get back on topic I only meant the Filioque in the Nicene Creed to serve as an illustration on how people can interpret either scriptures (or traditions) differently much like the “Rapture”. Perhaps I should have used "sola scriptura". :O)
Actually, we are flexible on this. Our own Eastern Catholic Churches are not required to recite the filioque. It's really a matter of different conceptions of God, and differences in language. In a unification we would not require the Greeks to say it, and they would need to accept that we do.
SD