I know the system against the feedback farming isn't full proof yet, we're still working on some things so we always appreciate suggestions. The reason why service owners are not allowed to receive feedback for it is because they enforce it as a service policy to let the payments go through them so they can farm feedback from every service request their workers complete, thus leaving the other party no choice other than using them as a middleman, creating unfair competition between service owners and actual middleman/verified middleman services. In my opinion free middlemen should be able to receive feedback for their free services as long as the risk is big enough, I think that even with a small fee it's going to make a big difference in the amount of people actually using a middleman.