I don't compost any clippings from a manicured/weed free lawn. Don't think it would be a good idea to introduce any kind of chemicals to a compost pile.
The feed part does not concern me at all. But I would not add anything treated with a weed killer to my compost pile or use it as mulch anywhere near any plants I wanted to keep. If you want to compost it and put it back on your grass, that should be OK, but not on anything broadleaf.
That is my personal opinion. You can always check with the manufacturer (not the distributor. I would not trust the distributor to know) and see what they say. The dangerous chemicals may decompose so fast that it is not a problem, but I'd have to have a lot of assurances and then I would probably only use it on grass. I am not really a very trusting soul.
I'm of the same opinion as Ridgerunner....if you are planning on using that compost on your veggies. There's usually residual chemicals in those weed killers. My lawn was treated by the previous owner 3 years ago, and it still resists weeds, in spite of dog and kid traffic killing patches of it.