One other odd possibility - RUST!
I've noted brake rotor rust overnight with both my vehicles, and the first stop can be a bit "grabby" B4 it's worn off...
The Focus's clutch has exhibited a "squeak" on engagement under the same circumstances - again going away after used a couple times..
Shifting is particularly "notchy" between first & reverse as well. Again going away quickly.
There are a couple ways the clutch could "hang up " a bit under these circumstances, and I bet BOTH are in play to some extent.
Being an "Elder" (grin), I'm kinda used to vehicles not working exactly as they should until they warm up a bit & get some exercise - I even remember the first vehicle I owned that amazingly (at the time) actually drove properly from dead cold with NO "hiccups", and at ANY throttle setting! AMAZING!!!!
I actually worried at the time that people would start damaging their engines by running them too hard when cold, just 'cause they COULD.... ( I've actually only seen this happen once, and that was exceptional circumstances on a motorcycle engine).
Back to the "notchy shifting" - saw this as a factory issue on BMW cycles years ago, when the factory had an issue with workers not lubing the input shaft of the tranny on the assembly line. Shifting would get QUITE notchy when it rusted and the clutch plate couldn't move freely - all cured with some lube, but it took pulling the trans. back a bit (or off completely) to get the lube where it belonged... Now THIS example resulted in difficult shifting ALL the time, but a little of the same effect COULD be happening - it just goes away when the small amount of "rustiness" wears off...
I'm betting my Focus's "squeek" and extra notchiness on the first couple shifts on occasion is from some rust on the flywheel & pressure plate surfaces - as mentioned earlier, the symptom ONLY pops up at times when the weather has been right overnight to cause OBVIOUS rust on the brake rotors - my pickup is WORSE with these symptoms than the focus, especially the initial brake "grab".
Luck!