Where are you adding patio doors? losing the toilet?

No the other end by the sink

Where is the refrigerator currently? Is that a window just south of the sink before the bumpout? Will the patio doors swing in/out or slide? Can you move plumbing? Is there a dishwasher? What are the two black markings next to the stove and between the sink and bumpout? Are they immovable?

Thank you.

There's a freestanding fridge by the kitchen door on the left currently

Yes that's a window just by the sink

Haven't decided about patio doors- can flex this as needed

Plumbing can be moved if needed, although would be easier if kept by the sink

Two black marks are immovable unfortunately. They're the original load bearing walls- the bit beyond then (stove, sink etc) is an extension

Will you have a washing machine in the kitchen, as is typical in English homes?

Since you can move the plumbing and haven't decided on the patio doors yet, I'd try a few completely different layouts before working around the existing cabinets. The bay could work nicely for seating, but I'd also test a version with seating near the new doors since that's probably where you'll naturally want to sit.

It might be worth drawing the existing room to scale and moving the cabinets around virtually first. I've used this free 2D/3D planner for that kind of thing:

https://homdera.com/en/tools/home-planner

I'd especially check the walking space around the seating and what happens when the patio doors are open. You may find a layout that lets you reuse more of the current cabinets than expected.

IMO, I'd keep the seating in the bay. If you move it to the patio doors, that whole end is going to be tight and heavily weighted compared to the rest of the kitchen. You could move the sink under the window and put the dishwasher where the sink is now. That will minimize changing plumbing on that end. The only concern would be blocking the patio doors with the open dishwasher. If you have the patio doors open on the right and keep the other door locked, that would alleviate that. Putting the dishwasher to the left of the sink would put it on the other side of the wall. The stove seems okay where it is currently. I would put the refrigerator on the other side of the load bearing wall for easy access to the dining nook. Perhaps you could have a false floor to ceiling cabinet built between the stove and refrigerator to disguise the load bearing wall. How deep is that wall?

Are there currently any upper cabinets or only lowers?

Can you draw a to scale floor plan showing the lengths of all the walls, including any windows or openings?