Vuforia how to use captured images

Hi and sorry already, if this question was already asked elsewhere, in any case I have found nothing on the first go to it and the documentation of Vuforia helps me just not further - or not found (also first time ever asking for help in here :smiley: )

Vuforia and ImageTargets work so far so well for me in Unity, but unfortunately I have to recognize certain images as targets multiple times… which Vuforia does not support (https://forum.unity.com/threads/detect-multiple-occurrences-of-the-same-image-target.511955/ ). Specifically, I’m concerned with detecting circles/crosses/empty squares in a classic TicTacToe game. Circles and crosses are known to appear several times and to use each field as an ImageTarget is 1. way too many options and 2. not different enough to be recognized reliably.

That’s why I thought about capturing an image (e.g. via ScreenCapture.CaptureScreenshot or similar), cropping it (in my case into 9 parts, Texture2D CropArea, I haven’t thought about this yet) and then checking each captured image individually to see if my ImageTarget is included.
And this last point is exactly my problem. I know how ImageTargets are applied to the CameraView (On Target found() function, consider/hide videos/models on found()/not found() etc.), but not exactly how to run over these captured photos, is that even possible for this to happen “in the background” with Vuforia?

Sorry if this is a stupid question, I don’t really know all the Vuforia functions yet.