I carry a universal remote with me at all times so that I can disable motion smoothing on any TV I come across.
That big battery sitting atop a camera is the silliest, least ergonomic solution I can think of. Two words for you: "Battery. Grip."
"However, ProRes is really just an imitation of Avid's DNx platform..."
ProRes - 2007
DNXHD - 2008
Use what you want, but a $40 dongle isn't enough to make me want to change workflows, fight with drivers, viruses, etc.
Panasonic is always loath to comment on DR. Several video reviews from early users state 14 stops, but that seems unlikely. Others have said "improved highlight roll-off" which seems more likely.
The GH5 is the camera for you. Panny had to make some trade-offs. By jettisoning IBIS the GH5s can work in scenarios the GH5 cannot.