Feature request: PPPoE server persistent graphs

I’m running MikroTik PPPoE servers with freeradius for AAA. One problem is that traffic graphs for PPPoE interfaces (as well as their dynamic queues created by Mikrotik-Rate-Limit RADIUS attribute) disappear when connections are lost. Would it be possible to preserve them (not delete when disconnected, append when connected again with the same PPPoE login name)?