Does that card have a eeprom on it? I dont see one at first glance

You don't need to change the BIOS to use it as an IDE card - use one drive and set it as the array and it will work fine. There will be a slight increase in boot time as the card's BIOS screen comes up and it detects the drive, but that's more than made up for with the increase in drive speed over the usual ATA 33 speed of the type of motherboard this card would typically be used with. If it were mine, I'd update the BIOS to the latest one (if it isn't already) and use it.
https://www.promise.com/Support/DownloadCenter

Repo Man11 wrote on 2023-11-16, 02:05:

You don't need to change the BIOS to use it as an IDE card - use one drive and set it as the array and it will work fine. There will be a slight increase in boot time as the card's BIOS screen comes up and it detects the drive, but that's more than made up for with the increase in drive speed over the usual ATA 33 speed of the type of motherboard this card would typically be used with. If it were mine, I'd update the BIOS to the latest one (if it isn't already) and use it.
https://www.promise.com/Support/DownloadCenter

Say I wanted to change the bios. My use case is the IDE cable is connected to a CF adapter. I use it for flashing images to CF cards as the USB CF readers can be flakey when making or creating .IMG files of my CF images.

I've updated the BIOS on a number of Promise cards over the years, but I've always used the tried and true floppy disc method; I have no advice to give on using CF cards or adapters since I have no experience in using them.
Also, check the BIOS version on the card - it may already have the latest BIOS.