Do you happen to have other proprietary wav chunks to store tempo btw? I'm interested in reading tempo (& any other kind of info) from something more reliable or precise than the ACID chunk. Although I can assume that at Sony you keep using the ACID chunk.We (Sonic Foundry/Sony) defined a 64 bit RIFF format so that very large files could be created.
(I know that Syntrilium also had a chunk for that in Cooledit, but could never get any info because Adobe is impossible to reach)
It would be easy to define yet another new chunk, but it would only add to the mess that the wav format is.