See the response to my question via e-mail. Perhaps some of this overlaps with the (sparse) on-line documentation of matroxcam, but definitely some additional information that I found helpful:
"matroxcam does not have functionality to set the number of frames per trigger. matroxcam is a much simpler interface than "videoinput"(using 'matrox' adaptor) and it only acquires a single image at a time by using the "snapshot" function. Currently, to acquire multiple frames, multiple "snapshot" commands are required. Because of this, frames-per-second performance is dictated by the general MATLAB code execution speed and what else is executed in the MATLAB code while acquisition is taking place (for example data processing or saving an image to a file).
For comparison, "videoinput" uses an image acquisition engine with buffered acquisition that runs concurrently with the execution of MATLAB code, and would be better suited for acquiring an image stream.
matroxcam does not currently providing a programmatic way of configuring hardware triggering, but it might be possible to achieve hardware-triggered acquisition if this is configured in the specified camera file."