Personally I would feel that jumping from 800 grit to the compound loaded leather belts would be too great a jump.
I would perhaps sharpen with the 800 grit belt, then hand sharpen with the green diafold, then strop on the leather belts VERY lightly.
If you apply minimal pressure while on the leather belts I fear you will ruin the edge by dulling it. You will only want to be touching it VERY lightly, the edge that the green diafold can give you will be almost razor like and pretty delicate and I find that if I strop too hard, minimal pressure being too hard (and on a hand held paddle strop not a machines belt), I can bring myself back a step and it will no longer shave hair,
A convex edge in my opinion won't matter in the kitchen, I have heard that the chisel grind is loved by some because where cutting through say a cucumber with a V grind, as you push down the blade forces its way through the vegetable and as it gets thicker, 'pushes' the vegetable apart bruising it slightly. Compared to a chisel grind \| where the flat side won't push against the vegetable as it goes through/down but the grinded side will and as such will help to push the thin slice of cucumber away from the knife meaning it doesn't stick to the blade.
I've used a polished edge to cut through a tomato fine, I think the idea that the polished edge is not able to cut as well through a tomato than a coarse edge with some teeth is from mistakenly putting too much pressure on the blade when polishing/stropping as I mentioned earlier and thereby dulling the edge. Also in the average kitchen a blade would sustain a bit of damage to the edge, as all blades do when we use them, and if not maintained regularly enough will start to dull, at this point in time if two knives experienced the same treatment but one started polished and the other coarse and toothy then the toothy one would probably perform better on the tomato skin as a result of one of it's jagged edges catching on the skin of the tomato and tearing through. The polished edge, having received the same treatment and starting out a lot smoother would likely have an edge that has rolled over and even though only microscopically, it's enough to mean that the smooth side of the edge and not the edge itself is what is sliding over the tomato skin and being smooth doesn't 'catch' and tear through like the coarse edge would.
That's just my theory, though the argument of polished vs toothy is an ongoing one, to sum it up I guess I would say that the polished edge is wonderful but requires a lot more upkeep than the coarse edge, and a fresh polished edge that can't cut a tomato is one where too much pressure was applied and the delicate edge was dulled.
Wow I wrote a lot! Hope it helps. You probably would have gotten a lot more responses and from people more knowledgeable than myself had you posted in the maintenance section instead of the kitchen cutlery one.
