Glaring flaw #1 --
The SSPX is not out to "make an agreement" at any cost. If that were true, we would have long since "sold out" by now like Campos and many other small trad groups.
The SSPX will never make an "agreement" with Modernist Rome. Only when Rome is serious about returning to Tradition will the SSPX be able to "lay down its arms" as it were. But when Rome gives up Modernism, it will no longer be Modernist Rome.
We have to let Rome know that we're waiting -- but we'll wait until the time is right. All in God's good time.
Matthew