My second small train [SGTools; 0 lvl]

it's not that all gleam links are forbidden (like 99% are, but there are some which are not), and not that only gleam is forbidden - platform which is hosting GA doesn't matter, what matters is GA requirements. GA posted on SG cannot require special actions (clicking reflink, registeriong accounts to get special key, solving survey etc) nor be involved in social account actions (liking FB page, retweeting, following twitter, joining Steam Groups etc). So if there was a gleam GA which would not require anything like that but just used gleam to make sure it will be 1 key per account - it would be fine to post on SG (but 99% of gleam GAs are used to farm social accounts and reflink clicks, so tghese are not allowed), at the same time if some othere webpage, not gleam, would offer GA requiring similar things it would not be allowed as well.