I don't like kitchen islands. As you obviously suspect, they break up the workflow of the kitchen.
The modern kitchen is outwardly oriented. The center of the room is open. Working surfaces are arranged along the perimeter of the kitchen in the form of countertops. The cook moves from work area to work area on what the military calls "interior lines".
An island interferes with the flow, essentially returning the kitchen to a configuration abandoned when Victorian kitchens were replaced by scientifically designed kitchens in the 1920s and the central work table where most of the work of preparing meals was done was replaced with countertops where the work is done in a modern kitchen.
If you intend to use the island as a working surface where prep work or cooking is done, then it will work well. Victorian kitchens were efficient in their own way. But, if the principal task areas are located along the perimeter of the kitchen, the island just gets in the way and impedes efficiency.
The minimum width of a kitchen with a central island is 160" (13'-4"), consisting of 25" of countertop on both sides of the room (25"x2=50"), a central island of 26" (The practical minimum) and walk aisles of 42" (the NKBA recommended minimum walk aisle for a one-person kitchen.). For two cooks the minimum width is 172" (14'-4") which allows for two 48" aisles.And, a more useful width for the island is 36", which brings the total room width requirement to 184" (15'-4").
If you don't have a room width of at least 13'-4", forego the island. It's not practical.
If you elect to go with an island, then place the primary task areas on one side of the island. Use the other side for secondary tasks and storage. You do not want to have to walk around the island to go from one primary task area to another.
Here is a rough example:
Good luck with the project.
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