The signature didn't play a role for the merit I got at all. In the very beginning I joined a project which turned out to be scam and of course I didn't got paid, lost a few months and decided not to join any campaigns as they were waste or time and the merit system came in the meantime. Then I was wearing no paid signature for a couple of weeks then joined one project of Tokensuite as I thought they were reliable, but unfortunately another disappointment.
Finally found a campaign by izanagi narukami, which was only two or three weeks but I finally got paid.
During all that time I was receiving merit without any problems.
So the conclusion: no matter if you are with paid signature for altcoins/bitcoins or without signature at all the merit are coming because of the content you are posting.
Actually, I still do not see why some people eager to upgrade to higher ranking member. To me, as long as I can read and can make a post, merit wouldn't make any different in anyway.
Because they are want a more income with bounty, but they not useful for another forum members and print only bounty reports, because on the forum many newbie.