Craig,
The concept of the patio block was to provide the support necessary to be able to take someone stepping on the crossing without the crossing suffering damage. Your concept to later pick the track up and install ties is not all that bad, provided you make certain to solder strapping across the gauge on all four sections to keep gauge while you spike the rail to the ties. I would also recommend using some construction adhesive on the tie to patio block connections to add additional stabilization.
Great minds will always overcome the obstacles.
Bob C.