I'm just thinking from purely a economic perspective having more people developing and relying on Pakistan will be better for economic development and stability. I think Pakistan needs to be internationalized as much as possible-They could transit their goods for export there by land then ship it.Gwadar is much closer to Persian gulf/ME than any Indian port so might be cheaper. Pakistan should also allow India land access to A-stan seriously hear me out- We should wait till they invest there as much as possible then give them exactly what they want at the last minute lol .
It would cause Indians effort to go down the drain, Chabahar would essentially become somewhat redundant and possibly fail,drive a wedge between India and Iran (India be silly to turn down a much cheaper and quicker Pakistani route),bring more money into Pakistan from transit fees,Increase their dependence on Pakistan making us even more strategically important as well as give us a degree of control over what goes into Afghanistan from India. I think it would actually be a master stroke from Pakistan.