I believe that the closer one can come to systems such as these, the more effective the ceiling capture and containment will be.
http://www.kitchen-ventilation.co.uk/heydal
https://www.halton.com/dh/EAAS0yFGPNRGhAEilsGFd5lGp5o3tnB57kERMMHZ7MN0z7jjlfe10OV2aF47oEKv_J_sp7DS-MiNMiKhdZ9iHROiFNdXjAbr72R36bqDw7hCtbZsAceIlTGBzcIQTj4jUk9R_9fvr9xheKrnYw/Halton-FS-Capture-Jet-Ceilings-Solutions-uk1004.pdf
Otherwise, the size of the collecting aperture should be at least that of a 10-degree from vertical expansion from the boundaries of the cooktop, plus whatever additional offset is determined from the particular room's draft direction(s) and speed(s).
At heights higher than 8 ft, one might get away with as low as an actual 60 ft/min containment air flow (60 CFM per square foot of aperture} rather than the nominal 90 ft/min of hoods up to 7 ft from the floor. This is guessing based on gas cooling, and not technical data which is almost always related to commercial hoods set at 7 ft. Blower rating, of course, will have to be high enough to achieve this depending on filtering and MUA. Really hot gas cooking, e.g., serious wok BTUh levels, will require more.
The greatest difficulty with flush ceiling collection schemes is that there is no capture volume, and spillage will be guaranteed unless the velocity of the air through th baffles is sufficient to entrain all of the plumes hitting the ceiling.
Please review the first dozen pages, more or less, of the Greenheck Guide for insight, most recently available here:
https://www.tagengineering.ca/wp-content/uploads/2015/02/KVSApplDesign_catalog.pdf
I also look forward to any reviews out there, not having seen any so far that I recall.
Q