(Thanks to /u/O_MORES for posting this elsewhere)

There’s a brand new HD audio driver for Windows 98/Me called WDMHDA.

Since it’s a WDM driver, it will play nice with the Sound Blaster Emulation Layer built into Windows 98/ME (sbemul.sys).

And it actually works. Here’s Windows 98 and this codec tested on a Ryzen 9 PC: youtu.be/uhWyH0TsrCc