I usually wear a thicker leash(it looks pretty ridiculous tbh) on larger days, but in no way could imagine it cutting my finger off. I wear a thicker one since I have had many snap on me before, and even on normal chest-head high waves. I do notice it a bit more, but it actually gets tangled up a lot less than a usual leash.
Have no idea where I bought it from as it is several years old but for those complaining about their leashes breaking you may want to look into it.
Most life guards dont really say anything about leashes unless your losing your board, or just look like a complete kook.
I usually have a good time on this retro single fin circa 1970 without a leash plug. Good for the summer days, but thats when there are loads of bennies that will get hurt by a board flying on some whitewater