What frustrated me was the poor support for pcmcia cards showed. Basically are supported cards for communications (ethernet, token-ring, fax-modem) and flash memory storages. I think it's useless this type of cards when we already have in T61 an ethernet port and other means to work with flash memory storage cards.
So, PCMCIA is sort of supported with Richoh adapters. Okay, but that doesn't mean it will support a sound card. Remember that support for PCMCIA was abandoned by IBM, before they abandoned OS/2. I doubt if any PCMCIA sound cards existed when PCMCIA was abandoned. As I said earlier, you probably need to get the PCMCIA support installed, before loading the UniAud driver (UniAud doesn't know about PCMCIA, so it won't wait for it). I don't think that is possible.
A Fax/Modem pcmcia card would be useful I think, since internal CXT soft modem of T61 not works with OS/2. However an external usb modem is more easy to find (besides the fact that the only use I make today of a modem is to remotely access my old Paradox security system at home).
I have a Fax/Modem PCMCIA card. It "works", but is totally useless because I no longer have a telephone line to connect it to. I think there is ONE (and only ONE) USB modem that works with OS/2. Again, there is no demand, so nobody has bothered to even try to make them work. I also think there is ONE, and only ONE, software modem that will work with OS/2. Still useless without a telephone line to connect it to.
So, I think try to do Audigy 2 ZS Notebook work with OS/2 PCMCIA ends up being a waste of time.
It is an interesting idea, but I doubt if you can make it work. Audigy sound cards are supported (somewhat) by UniAud, but UniAud knows nothing about PCMCIA, so you would need to find some way of loading the PCMCIA support, before loading UniAud. Even then, it may not work.
Over that past 20 years, or so, I have used PCMCIA to test if it will do anything. It is a terrible thing, that doesn't work with SMP systems, so you do need to disable SMP support to even try it. Then, you need to find the proper driver for the device (that knows about PCMCIA). Then, you need to configure PCMCIA to manage the device (that can't happen, if the device driver doesn't know about PCMCIA). A "waste of time" is an understatement. Of course, if you can write your own driver, it could be an interesting project.
Express card adapters are slightly different. Express card connects to the PC bus, directly (no driver required), so an OS/2 driver (if one exists) can find it at boot time. I have a StarTech USB 3 Express card adapter, and it works okay, with the XHCI driver from Arca Noae, in my Lenovo ThinkPad T510, and my IBM ThinkPad T43. As usual, YMMV.