need method to always update instance description even if filtered

I am not sure exactly how to describe this other than by example.  We created an API-based method a while back to control alerting on interfaces based on the interface description.  This arose because LM discovered interfaces that would come and go (e.g., laptop ports), and then would alarm about the port being down.  With our change, those ports are labeled with a string that we examine to enable or disable alerting.  The fly in the ointment is that if an up and monitored port went down due to some change, our clients think they should be able to change the description to influence behavior.  Which they should.  Unfortunately, because LM will not update the instance description due to the AD filter, the down condition is stuck until either the description is manually changed in LM or until the instance is manually removed in LM.  Manual either way, very annoying.  My proposal is that there should be a way to update the instance description even if the AD filter triggers.  Or a second AD filter for updates to existing instances.  I am sure there are gotchas here and perhaps a better way exists.  I considered using a propertysource, but I don't think that applies here.  The only other option is a fake DS using the API to refresh the descriptions, but then you have to replicate the behavior of many different datasources for interfaces.