I Agree with your route Via Unnao...But Via LKO it's Horrible...!
Time need to be Aggressive as It is Humsafar with Flexi Fare.
Prayag 21:15
Ucr 22:50
On 00:25
Cnb...
more... 00:55
Anvt. 6:20
I think for the time being ALD Duranto Extension is best Option and Separate Rake can be used for train to Mumbai (If Possible)