Frame rate logging in Simulink

Hello! I am using a USB3 vision camera to acquire images using the Gen-i-cam interface in Simulink.

The images are used to send UDP signals of pixel positions from a blob analysis block. In parallel, the images are also used to detect motion using feature detection. In 'From Video device', I have set the block sample time to "1/90". I used the following thread to compute the acquired frame rate from the camera and it was 110 fps:

https://nl.mathworks.com/help/imaq/examples/determining-the-rate-of-acquisition.html

But when I used the Frame rate display block in Simulink, it shows a frame rate of approximately 35fps. This leads to the following question:

1) Is this difference because of computation time per frame in Simulink?

I also noticed that the displayed frame rate is not constant and is fluctuating. I would like to log the values of the frame rate as shown in the "Frame rate display block" to analyze the fluctuations. But apparently, the Simulink library does not support this functionality at this moment. So I tried to extract the frame rate from the timestamps of the position signals I obtianed from the UDP signals, but it shows a constant rate of 90 fps, which I assume is the block sample time. This leads to a second question:

2) Is there a workaround to log the numbers that appear in the "Frame rate display" block?