That is a nice catch and makes me wonder...
It needs to be clarified!
Few days ago a user on fb group had his boosters reduced by Nordeus.
He was saying that he was not using vpn (we cannot cross check that) but he indeed was farming having lots of boosters trough legit local ads.
Could it be that some monitoring TE system have some thresholds for total amount of boosters?
If I watch legit ads for some months and I manage to farm 4k green boosters, am I on the safe side?