Hi Willi,
Yes, we can modify our ASCOM driver to support more cameras, but there is a problem of the applications.
Like MaxIm DL, most of the applications do not support to use the 3+ cameras at the same time. That's the reasom why we did not program the ASCOM driver to support more cameras.
So I think a better way to use the 3+ cameras is native driver. If you can use the native driver to connect the cameras, you can visist all of them at the same time.
Thanks
Chad