On site my camera is tripod mounted with a clip on the center post that holds my phone (a Note 5 - it's quite large) which serves as a remote and a bigger display for the camera via the DSLR Controller app. When I move, the whole rig moves as one piece. I level my tripod at a consistent mid chest height and rarely change that height. That gives a consistent look to the entire set of images. I use a 7 shot 1 stop bracket that my 7DII runs automatically and my remote setup allows touch screen focus on the phone. I can estimate the exposure quite accurately by sight on the phone's display and, since I use a 7 shot bracket while I plan to only blend 3-5 frames, I have a good deal of leeway with regard to exposure. The result is I can shoot a 3000 sq ft house (usually about 50-60 final images) in a little over an hour and rarely take more than 1.5 hours for larger houses. I could not do that with flash because because set-up for each shot is more tedious and required some testing and repeat.
In addition, using available light lets me get a more natural look and it especially lets me tie several areas of the house together in one exposure in a very natural looking way. I use flash some - usually in smaller rooms - and like the very clean look with no color shifts, but my clients like the blended images and are very outspoken about that.
The result of this is that I spend more time in post (maybe that's the time you want to save) but I kind of enjoy that and I've gotten quite efficient about post. My computer has a good deal of RAM, a fast quad core processor and my main HD is an SSD. I can usually finish PP in about 2 hours because I rarely have to wait on the machine.
Bottom line (I really dislike that expression), I prefer the available light look and it doesn't slow me down.
I prefer spending more time in post as well because I really enjoy post. I'd rather spend less time on location. What are you using for a cable setup to get your phone into your camera?