Second, you should send a polite note to any another member, if you notice anything that isn't quite right, their link is full, they are leaking routes, or something just looks weird. We are a community, talk to your neighbors, be their early warning system. Hopefully, they already know about what ever it is, but we are all busy and things slip through the cracks all the time. So if you notice something that doesn't seem right, let your neighbors know about it. But be polite about it, next time it might be you who has something weird happening.

Third, the IX is an optimization, if you are having issues sending traffic to another member you have other routes, use them. We have had to do this, not because the other member ignored us or wouldn't upgrade their link, but sometimes upgrades can take a little time.  A few weeks or even a couple months to complete an upgrade isn't that unrealistic and not uncommon depending on the circumstances. Not everyone has extra 10G or 100G ports just sitting around, and if you have to backhaul the traffic, arranging that upgrade can easily take several months.

The policy we have for remote switches makes sense, but members need to manage their own capacity. Even if we were to forced them to add port capacity to the exchange the bottleneck could just move to the next hop. None of us has sufficient visibility into the other guys network or business to be making those kinds of judgements for them.

If someone's port is full on a regular basis, having someone from the Board contact the member and ask if they are aware of the issue seems approprate and reasonable. Basically asking, "have you noticed your port is full quite a bit lately?" But its the member's responsibility to manage their network as they see fit, including their ports to the exchange. 

Thanks