No. I already have/run a known and reliable routing node. I don't need to advertise its existence, but I want to incentivize more routing to happen. Negative inbound fees don't mean that I don't earn fees.

C_Otto

lightning

My inbound fee policy for c-otto.de

Ok, so if the goal is to become a routing node, the idea of low or negative routing fees is advertising perhaps.  Become a known, reliable node and eventually turn on fees to recoup the cost.  I would love to follow your experiment with data as you have it.