Is it possible to get this board, LAY-31399_C.brd, as an ASCII file that I can import to Altium please? It would be something like LAY-31399_C.brd.alg.
It appears that NXP has made the ASCII export file for Altium available in the past. I can search through this site and find several examples of where that was done. Has your policy changed? Is it just this board you will not convert?
The policy is to provide only the files as available on the Design Files bundles. However, there may be users in the forums with an Allegro license that have been willing to help exporting the design in this format.
My apologies for the inconvenience.