Dealer advised the screen on the camshaft broke in half and they couldn't find the screen so the verdict is this:
Replace Cam Shaft Cam Bridge, Tensioners, Timing Covers & Timing Chains. Quoted $4200...
I'm debating of having them fix it or possibly doing an engine swap....
$4200 to just replace those items, so that much to change out the timing chains and cam bridge? If so that's about $2000 too high even with the cost of a cam bridge factored in. There must be something extra they planned to do in that quote (I hope). That quote is closer to the cost of a head swap than a chain job.
Replacing chains and guides aren't much extra work over a standard tensioner replacement job and you need to remove the cam bridge to change the chains. I just did my chains recently and luckily found my cam bridge screen stuck against the side of the cylinder head. It's a tiny piece of screen. The attached photos show how small it is and the arrow points to where I found it on the head. I didn't realize it was there when I took the photo so it's not very clear. I chose to break the rest of the screen out of the cam bridge and reinstall the old bridge since they're known to pop them even after short mileage and that bit of screen floating around can lead to other issues. A new cam bridge costs over $200 online and has the same screen design as before, so I skipped it.
My concern would be how it lost 3+ quarts in 5kmi. If it wasn't from an obvious gasket leak then you may want to look into having a private shop swap in a used engine instead. Just have them check the used engine for the updated tensioner through the lower timing cover inspection hole or have them install an updated tensioner and a fresh rear main seal in the replacement engine before installation if you go that route.