The Vybrid Security Reference Manual (VYBRIDSRM) does contain such information, which, unfortunately, cannot be published here. The best way of getting it would be via a local Freescale FAE in your area.
Thanks for your reply. I have access to *VYBRIDSRM" and have been unable to locate any documentation in that document related to the maximum PKI length supported when using HAB. There is a Freescale training video Security Solutions: Security Features of Vybrid Controller Solutions Built on ARM® Cortex™ Architect... has a slide with some details but I've been unable to find any documentation with the maximum supported size. I'll contact our local FAE for additional details.
I was unable to find an answer to this in the Vybrid Reference manual. There may be an answer in the Vybrid Security Reference Manual (VYBRIDSRM), but I do not have access to this document currently. I will let you know what I find when access is granted. If you have access and are unable to find an answer, the Freescale Vybrid Design Team would have more information.