If I understand correctly what you mean, I think so...
I have used stills previously, but not 'matching' stills.
What I am proposing going forward is ensuring my video and stills match perfectly in the grade and if frame grabs intended to be used as stills, identical to that exact frame in the video.
The primary intention and purpose is to cut back drastically on stills photo capture in the first place and therefore also editing time and move towards a more cohesive and less time intensive approach.
So currently I'll do a full capture, cull and edit etc on both photo and video.
Going forward, I'd like to capture even more video and reduce the stills capture back to just certain elements, mainly details and family groups.
Pics will be captured in raw + Jpeg 3:2 ratio with my LUT baked into the Jpegs (which is the same LUT I bake into my video footage in camera). I normally bin the Jpegs and use the raws, but I am proposing using the Jpegs and simply keeping the raws as backup just in case.
Edit the video timeline to the point where it's still in 3:2 open gate format and then pull the frame grabs for use specifically as stills, rather than to insert back into the video.
I can then go back into the timeline and put my more 'cinematic' 17:9, or 2:1 or whatever crop on it, and add all the twiddly bits that are video specific such as any text, transitions etc.
Et voila, a finished wedding film plus a set of stills that look like frames from a movie. As intended, ie, when someone says, "your photos look like frames from a movie", it will be because most of them are.
Anyway, I am going to give it a go as all last year, this year so far and the next 2 jobs, I've been shooting stills on the A7RV and Nikon Zf with 90% of the footage for my wedding films coming from the S9.
After these next 2 jobs are in the bag, the A7RV and Zf get replaced with a single S1Rii shooting 7.2k 30p clips and the S9 which was shooting video exclusively at 6k 30p, will be shooting a mix of some stills and some secondary video.
Pretty sure it will be a good set up based on the kit I have and some of the trials I have attempted, but as with all these things, it's only when you climb out of the trench and charge the enemy, with bullets flying, you truly know. Or you step on a landmine and it all goes tits up.