Lawn mower blades can be sharpened and balanced. Buy extra so that one can be in the garage waiting to be sharpened while you're out mowing with a fresh blade. Easy to do yourself or have it done for a few dollars.

I'm absolutely all for option #1.

Agree with Rhizo-I've done much the same for over thirty years at my place. No sycamores, but lots of other trees. Chopping up leaves/other tree debris with the mower is the way to go!

+oM

Get a bench grinder and some extra blades. Sharpen them yourself and change them. It's worth it to have two nice trees in the yard. If it was my yard, I'd probably pick up the big pieces before mowing.

Yes, of course you would not want to chop up larger limbs with the mower. And I agree also, sharpening up mower blades is fast and easy. I even do mine with nothing more than a vice and a file. Takes maybe 15 minutes, all told.

Sycamores are great trees where they are native and well-adapted. We're a little north of their true home range up here but they still grow well. Down in Illinois is where I see nice native groves of this tree. Very worth having, IMO.

+oM

I have monster sycamores on my land, and my shade garden is right under the one nearest my house. That sycamore also shelters hornbeams, Black haws, and one Halesia. Yes, it drops small limbs, and leaves, and bark, but it's a great tree for shade gardens because it doesn't have fibrous roots. I grow an enormous range of woodland plants, some native, some not--Trilliums, Erythroniums, Va. Bluebells, Epimediums, gingers, Hellebores, primroses, Dodacatheons, Cimicifugas, Allegheny spurge, and on and on. Take your "lemon" and make great lemonade.

If you wait for a day when most of the leaves are kinda dry, (on the ground) I would put them in a tall garbage can, and keep adding them, if they are truly dry, you can keep smashing them down into the garbage can, making them crumble, and they can be used to supplement wood mulch, put the leaves down, then use some wood mulch to hold those leaves down from fall winds, or whatever time of years winds, or simply compost those leaves with any greenwaste you have. BTW, I love Sycamore also, I have a baby growing in a pot, I was able to get a seedball this spring with viable seeds on it from a tree I planted back in 1996. It may be hard to get the leaves to dry out good. Hopefully the OP can get a dry stretch when the leaves fall in spring. Hope that helped.

We have a sycamore out front that grows like a weed. the leaves are big too. personally I don't care for it, but my Mr. loves it.