What formats/codecs are the source footage in? H264/H265 can get rough especially in higher resolutions/framerates and I would recommend trying transcoding the footage to Prores or DNxHR to see if that would speed things up.
Mocha still requires tracking and/or masking to set what you want to remove, and it might not work that well on a timelapse where things are jumping around frame to frame.
The license card itself says to keep it safe as they will not be replaced if you lose them. You’ll need a new license and I’d suggest taking a photo of it or writing the code somewhere safe.