If I was going to set up a 'self launching' system I'd see if I could replace the gypsy with a new one. By doing that you have the option of sizing it for any chain you wish. Also,,, an old gypsy can get sloppy in holding the chain as the edges get worn. Replacement gypsies are pretty much standard and available.

On the subject of all chain or a combo of chain and rode,,,,, I wouldn't give it a thought,, All Chain! Perhaps 250' of chain backed up with 75 feet of rode that you will hopefully never need. With the 75' of rode you can use it for stretch in a good blow and if needed you can cut it to put a floater on it for retrieval. We have spray painted 3 feet of RED 10 feet from the end of our rode with a loop and whipping to tie the floater to. A wide black line after the loop and whipping around the line for the cutting spot.

Chain has so many advantages there is no argument.

Except for Larry and his tri.