Indeed, I can confirm that this happens even with two entries, running 4.3:9506574:
[root@allegro-4 ~]# kamcmd -s /tmp/kamailio_ctl pl.stats PIPE: id=bg350_ingress load=0 counter=0 PIPE: id=bg208_ingress load=0 counter=0
[root@allegro-4 kamailio]# curl --digest --user:pass http://10.150.20.6:5060/csrp_rpc/ --data '{"jsonrpc": "2.0", "method":"pl.stats", "result": "0xd"}'; echo { "jsonrpc": "2.0", "result": "PIPE: id=bg208_ingress load=0 counter=0" }
-- Alex