I've talked about why mafia using the RBer this way is a bad idea for them but I'll do it again. In order for mafia to get any mileage out of "faking a green check" the green check needs to be on mafia. If, for instance, ten people claim targets and one of them is on mafia, and the mafia RBs that person, then they have a 1/10 chance of giving themselves a green check and a 9/10 chance of wasting their roleblock. The hider generates a lot of value for town as the game goes on and so rather than gamble on a longshot that will rarely pan out and won't even generate them a ton of value if it does, the mafia should rather be much more interested in getting rid of the hider asap, and use the roleblocker to increase their chance of doing that (and decrease their chance of missing a hit, which gives town an extra lynch).
for the same reasons, making mafia have an easier time killing the hider is a bad idea for town.