Mysore side train can be extended with few changes in TT. But expecting SUR SF and Gomateshwara are not going to happen. In fact, it would create more issues as people want these trains to touch SBC.
If long distance trains are going to get extended, I would say extend BAND ERS SF (thrice a week). Instead of terminating at BAND, it can go from KJM to YNK to DHL. Another option would be Salem YPR passenger with loco reversal at BYPL (change over from Hosur line to Yelahanka line). Slowly YNK...
more... can be developed as a terminal.