It appears `Cha0s, erstwhile admin of pr0gramm, after transfering admin duties to `Gamb pursued different ventures. It seems he developed coinhive independantly of pr0gramm and it's team (I can't verify this, but why not). The product was tested on pr0gramm some time ago, where users would run the miner in exchange for premium account time. The coinhive site appeared after this(, as far as I remember without mention of pr0gramm or identifying the admin as `Chaos). I don't know of anything proven beyond that.

(Edit) See also: https://news.ycombinator.com/threads?id=pr0gramm pr0 "official statement" https://img.pr0gramm.com/2018/03/26/6300254f309e8f69.png

I should add that I am not affiliated with anyone here, just a user of that board.

coinhives earlier state was tested on pr0 with their permission

It also has to be noted that everyone testing the "prototype" coinhive code knew that he was mining and had to manually start the miner. Coinhive also stops the payouts to all websites that get reported for the illegal use of it.

As far as I know did the old pr0 administrator developed Coinhive and tested it together with the new admin on pr0gramm.

But when he developed Coinhive he didn't even was pr0s admin anymore. Krebs assumed that the new admin is involved with coinhub and doxxed him too.