Tested all configuration:
Macbook pro 13, 2017, 16gb, 3,5i7, Mojave
Macbook pro 15, 2017, 16 16gb, Mojave
with
Blackmagic UltraStudio Mini Recorder + Panasonic G9, tested 720p30, 720p60, 1080p30 input signal
OR
Blackmagic UltraStudio Mini Recorder + Sony a6400, tested 1080p60, 1080p30 input signal
OR
EZCAP-265C HDMI-to USB-c Card (work as webcam) + Sony a6400 tested 1080p60, 1080p30 input signal
OR
EZCAP-265C HDMI-to USB-c Card ( work as webcam) + Panasonic G9 tested 720p30, 720p60, 1080p30 input signal
output was: hdd record only, 720p30, tested h264 and HEVC
all of these options inhibit the system
I note the observation that after the first start of the program, the follow function works without overload, but literally after several inclusions it starts to slow down again. Perhaps this is a buffer overflow or some kind of stack problem.
the Rendering Performance monitor shows that the Follow layer is eating up the rendering performance. However it meight not be the problem by this particular layer because I think there is a conversion happening for the BMD Minirecorder that needs to be done to enable the layer to use this video source. This conversion is happening in the rendering engine. You may test this by adding any video filter to the BMD source. This will cause the conversion happening outside the Rendering and should bring the Follow layer to a reasonable performance.