Attached is the full layout of our kitchen for context.

You will end up using the space between the sink and stove as your prep area. It is unlikely that you're going to use the prep sink in the island very much as it will not be the most direct space between the sink and stove. The amount of space between the sink and stove does not look very large. You may want to reconsider that design. The ovens are in an odd location, not only will you have to cross your workflow areas in order to get to them but they are almost in a different room. If you don't use them very often this doesn't matter but if you do, that location may be troublesome (also if you don't use them very often why bother with the expense of two ovens). I cannot tell from the drawing what is next to the ovens but you will need to have a landing space where you can put things down next to the ovens conveniently. If one of the ovens is a microwave then I think they are in the wrong location as I find that I use the microwave frequently for little tasks while cooking other things and having to walk all the way across the kitchen would be a problem.

What are the three x'd out areas in the main floorplan (two on either side of the utility room entrance and one next to the pantry)? Is that dead space that could be used?