i think open pugs are completely fine and i can only think of one blatant alt that ive seen playing RGL pugs and i think he is banned now anyway. i think the only reason open pugs can be bad sometimes is when theres a big disparity in skill between the players added up and creates uneven pugs, but thats better than never getting to play at all honestly. im also very glad most of the adv/inv players are playing captain pugs now, because getting raged at by higher level players was so unfun and getting rolled by them was even less fun
however i do also maintain there shouldn't be elo gains and losses for pug wins/losses. it should be a fixed value based on your highest level played (with maybe a cutoff, if you played advanced in like, season 3 with a 6-6 record and havent played in a trillion years) and then it should stay that way and be used to balance the pugs, similar to tf2pickup