Not only Fred Flintstone, but CitrixEngineer also uses the CD IDE channel on a sound card!
I have a DVD and a CD-Writer connected to an old Creative Labs AWE 32 - and it works fine.
I need to do this, since the system in question has 4 hard disks, occupying the entire UDMA33 PCI controller.
Since the data throughput of 16-bit ISA is <>10Mb/sec, that's ample speed for both units. DVD is supposed to have a potential transfer rate of 15Mb/sec, but I've never seen that figure in a benchmark.
I use a RealMagic hardware DVD decoder, so DVDs are liquid smooth, and CDs burn in 10 minutes at 8x.
No problems with using old gear ;-)