ATEM SDK for 32-bit windows app

We've got a large legacy 32-bit app that needs ATEM support added. AFAICT, there's only a 64-bit DLL supplied now (BMDSwitcherAPI64.dll)

Is the 32-bit one available in any form, or is it totally deprecated?

I've found that the 32-bit DLL is provided with the 8.x releases. Is that going to work OK if the ATEM firmware has been updated to 9.x?