My wife and I are just a touch under 350lb combined and ride together all the time. With all of the accessories we have on the bike, when we're on it together we're almost certainly a bit over 350lb. We also often tow a trailer with our daughter and/or dog.
Out of the ~1,100 miles we have on the bike, I'd say ~400 miles have been with both of us on the bike at about 350-370lb depending on what we had with us, and then out of that ~200 miles were with the same weight on the bike plus towing another 40-100lb with the trailer.
No issues other than having to adjust the brakes pretty often, and of course the acceleration is a whole lot less than when I'm riding alone! We recently bought and installed the Juin M1 hydraulic caliper conversion kit, and would 100% recommend it. Makes a huge difference when we are fully loaded.