It should not lay on the fins. Just pull it up, copper will bend.

@outpaientzero this is a 15-20ft run of pipe so its own weight pulls it down. Are there hangers or lifts specific to this application?

You probably are going have to install some type of support to keep the return pipe off the fins. You can try using zip ties wrap around each of the brackets. There are ties rated up to 180F degrees which should be sufficient. If you need something with more heat resistance then look at using soft solid bare copper wire. If you use a metal wire then I recommend it be copper. Using a dissimilar metal could cause long term problems. The pipe has to be pulled up so it doesn't touch the fins but it should touch the brackets either.

The return pipe may be contributing to the noises, and should not lay on the fins. I imagine it would certainly affect the efficiency of heat transfer to the room. In my home, when our baseboards get noisy, it usually indicates air trapped in the system and needs to be bled.

I would try using heavy nylon zip ties to support the pipe - looping it through the gap in the brackets that are every foot or so. You only need about an 1/8 of an inch gap.

If the heat from the pipe is an issue for the nylon ties, any type of thermal break (cardboard) would limit the heat transfer.