very late reply to this, but stumbled upon this thread. I have been fooling a lot around with marked frames lately, and yes; they work, and yes they are weird. They do not operate by using frames directly, but operate on ticks. Default is 24K ticks per frame. For some reason I have also found I might have to divide the frame number with the frame rate first to get the correct “Frame Number”. No idea why, but this formula gives me forrect result: (TheFrameYouWant/FrameRate)*Ticks → Make FrameNumber → Find marked frame