FBX Custom Attributes get removed on Load

We need to load FBX files that were generated using Maya and Max into Blender. Using Max these models were configured with critical run time information based on the War Breaker Specification (used in the Modeling & Simulation Industry,) in the Object Properties Dialog. These FBX files work perfectly in Max and Maya but when importing the same file into Blender, this custom attribute gets stripped out. The custom attribute is "UDP3DSMAX" Interestingly if the Attribute is created in Blender than it can be re-imported into Blender, Max and Maya and it does not get pruned. Unfortunately, we have more than 1000 models made in Max and Maya, and we cannot re-import them all into Blender and resave them. We would have to reconfigure thousands of attribute records. This impacts our customers who have been very interested in using Blender but which I cannot recommend until this works. Maybe there is a work around, but it looks like a defect to me. Thanks