Queue member receiving multiple calls

I have searched and performed lots of R&D and finally conclude that when we used member as a SIP in queue we face the issue of multiple calls on already busy agent however is we used LOCAL channel as a member then we have no issue either we transfer the call Local agent remain incall or in use . However if member registered as a SIP after transferring the call status shows agent NOTINUSE
Actually I am looking for how we can configure same for SIP or how can we show agent still BUSY or INUSE after transferring call to any custom destination it would be appreciated if any one help me out.