I agree with you. Rake reversal is a major problem here.
I have done some independent research and found a solution to this problem. That is connecting DHNE-GTL and RC-GTL lines. Just before GTL town these two lines come very close to each other may be about 0.5kms, after Mallappa Gate.
If these lines can be connected in such a way that trains coming from DHNE go the RC-GTL line at Guntakal Chord Cabin, then rake reversal problem will be avoided, this will bring some bypassing trains back to GTL.