In theory, the chipset of the ATI 600 should work. But it won't be documented.
Most USB cards use an eMPIA bridge. And on those cards, the bridge is what controls the audio/video chipsets on the card. The 600 USB (and clones, which are clones due to same TI video chipset) use this bridge.
The infamous Easycap/EZcap (aka Easycrap) cards also use an eMPIA bridge, which is where numerous myths and misunderstandings came from. It's why some people consider all USB cards to be "Easycaps" (false!), or why some folks think an ATI 600 USB is "the same" as an Easycap (false!). Note that most of these myths have thankfully been exiled to the scrap heap, but 5-10 years ago, that BS was too often repeated. You do sometimes see that nonsense still repeated in Youtube commenters, but "those people" have largely moved on to even worse methods (Chinese composite>HDMI converters, or Blackmagic junk, the current fad in video butchery).
Anyway, there is some information out there on using Easycap/EZcap cards with Mac.
It is heavily dependent on the OS X version. As with WinXP, video capturing was mostly a task of 10.6.8 era, which each new version dumping off more and more "support" (rarely official support, just that it worked).
As an example, this: https://www.macupdate.com/app/mac/32004/easycapviewer
Mirrored from: https://bentrask.com/easycap/
Note: The ATI USB 600/clones do not use STK1160 chips. Those chips are why Easycap devices suck.
VideoGlide should specifically work: https://www.echofx.com/videoglide.html
The main downside here is 640x480 max resolution. But for VHS, 640x480 will suffice, and can be edited in FCP.
It's $30, but Mac is expensive, and buying software (that would be freeware on Windows/Linux) is not uncommon.
This would be my first attempt.
Remember, there was never a guarantee this card would work, but I think it can.