It seems most issues with cylinder deactivation relate to low gear performance, jolts and lugs, as discussed at length in this thread:
My 2018 mazda cx5, about 1000 miles. When I stop and then press the gas , I felt jerky and stuttering at the low speed sometimes. Is it normal or something wrong with the transmission?
www.mazdas247.com
In that latter pages of that thread is the following TSB as a possible solution:
file:///C:/Users/jdelf/Documents/Downloads/MC-10185048-0001%20(1).pdf
I had that TSB applied last week and since my initial impressions posted in that thread I've put on another 100 miles of local, less than zoom-zoom, driving. There are subtle but worthy improvements in my 2020. In trying to "manufacture" a jolt I was getting a not entirely unpleasant bump-zoom. I can now get it to the edge of a lug but it takes more effort to manufacture it and it is less notable and bothersome than before.
My pre-TSB impression that the low gear issues were not CD-caused per se, rather an engine-transmission integration issue, is on the way to being confirmed. I'm a driver, not an automotive engineer, but I think there's more to this TSB than just suppression of torque resonance. Or the question is, "What did they do to suppress that resonance?" I seem to feel a little more engine braking in the low gears and a little firmer gas pedal. I think they might have tweaked the torque curve and/or the power curve. It's a PCM change, not specifically a trans software update.
I had the TSB applied at the same time as an oil change--one year old oil with 4k miles. I doubt fresh oil would cause these kinds of differences.
All-in-all, so far, the vehicle behavior is now not outside the bounds of inherent limitations in a normally aspirated 4-cylinder 6-speed set up. Feels pretty good now, actually, pending more driving. I'm heading out on a 1,500 mile road trip on Sunday. I'll probably have a follow-up in that other thread after that.
Under the heading of “unintended consequences”, the gas mileage still looks good and no idiot lights have displayed—so far so good.
Or as one other poster said in that other thread with an enviable economy of words

, "It's fixed!" or something like that. I may join him in that declaration after the road trip.