You got it right as per recent discussion it will be tri-weekly, as people from Solapur were opposing this extn as daily, however extn agreed for only as tri-weekly just like Mumbai-Latur/Bidar Exp. This will run on those days on extended portion when Mumbai-Vijayapura FP will not be there, it means Cstm-Gdg on Thu-Fri-Sat and Gdg-Cstm on Fri-Sat-Sun. Now CR and SWR drawing plan to accommodate Solapur-Hubballi ICE, what should be done with train. In recent news there was even plans of new Sur-Pune ICE, may be rakes of this ice will be used there have to see.