Do you know how much slope you are dealing with? As in degrees of slope angle? There are free apps you can download for your phone to turn it into a slope gauge.
Mine is a cabbed tractor, which would raise my center of gravity a bit higher than your open station tractor. However, my rear tires are also filled with Rimguard, which lowers the center of gravity. Lol. So, we don't have exactly the same rig. I believe the overall affect is my center of gravity is now lower than yours, since I think the weight of the Rimguard far exceeds the difference between the weight of our 2 tractors.
That being said, I believe my wheels are set up in the second to widest position. The centers are flipped from ptsg's configuration, but I believe my rims can go "out" to the outer setting. With my R4's, I am hovering right around 70"s right now, from outside side wall to outside side wall.
Here is a pic to show you what my rim is set at now:
Also, the front rims can be set with either centers "in" or centers "out", but there is no additional adjustment between the rim and center. If you look at my fronts in this pic, and compare it to ptsg's picture, you can see the center dish on the front rim is "out" on mine vs. ptsg's.
With my wheels set this way, the front and rears track in the same wheel tracks as far as width goes. Bearing in mind that my rears are filled, I have been on side hills of 20 degrees, but only when the ground is dry and firm. It is all I would attempt, and there is much "pucker factor". That is also keeping my FEL as low to the ground as possible, and not raising my brush hog off the ground. I try to avoid this much side hill whenever I can.
If your slope angle is much less than 20 degrees, I don't think I would be too concerned. Just make sure any implements you have on are at there lowest position, and make sure the ground is fairly stable and dry. And of course, go slow, and avoid "bouncing" at all times.