Other than the obvious sweating and chaffing, the extra padding also tends to change your seat geometry. This may not affect you, but for most it does. It will put more stress on your joints and back. Very short 6-10 mile rides are doable with a reasonable modicum of comfort, but I would not recommend longer distances. In this instance, as is the case of doing almost all physical fitness while wearing protection, the thinner the better. I found that the Tena Flex range offers a fairly decent amount of protection, flexibility, and durability. The fact that they are a cloth cover means that you can load the ever living daylights out of it with your choice of powders. That will REALLY help to cut down on chaffing and keep the sweat factor to a minimum for longer. Also, the very large elastic single tab system allows for an excellent fit with extreme flexibility. Unfortunately, while the padding is absorbent it is the least durable part of that diaper. It will clump and become uncomfortable at a certain point of sweat exposure and activity.
I would suggest you start with a fairly simple ride to assess your experience. I would also suggest a different diaper as the level 3's are still a bit too thick for an activity like this. However…your mileage may vary!