Interesting "rainy day" question. My guess is that the lower the wheel speed, the more damage would be caused by a wheel side load. Just look at how flat the right side of a Road Bike (ten speed) wheel is and they do not have much side load "taco problems". It would be my guess that the road bike's higher wheel speed distributes the side loading to all 36 spokes around the entire wheel.
Many years ago, there was a Sulkey Racing track west of Phoenix, AZ. Our family's bike shop did the wheel repairs for some of the stables. The Sulkey's had the same challenge that we are discussing on your project. The wheels were held at a ninety-degree angle to the ground while they were going around the turn, lots of wheel side loading. The commercially built Sulkeys had a Bendix Sulkey Hub. It was just a wider version of the common Bendix quill heavy duty hub we still see today on bicycles and motorbikes. It was not the Bendix trailer hub, it still used a 3/8" axle and was supported from both sides.
IMO, the larger the spoke angle (to the ground), and the wider the spoke flanges are, the more wheel side load strength. It goes without saying, you need at least 36 spokes, and a strong rim. I still think you could repurpose something from a Moped and save some money.