I'd suggest let current Secunderabad Rajdhani go to Kurnool, anyway it'll be dependent upon Secunderabad only for occupancy.
By that virtue alone Secunderabad could qualify for a dedicated Rajdhani on more convenient timings/days.
Maybe a Rajdhani having early morning arrival at Secunderabad, since Bengaluru Rajdhani is there for evening arrival and extended Kurnool Rajdhani would be there for afternoon arrival.
Extension of current Rajdhani...
more... would be beneficial to Secunderabad IMO.
BTW how is Kurnool qualifying for Rajdhani ?? I recently saw a statement by AP CM at a ln investment conference in Delhi where he announced Visakhapatnam as the Sole Capital of AP if I'm not wrong.
There was some debate on IRI as well.