Quick question, how hard is it to launch this thing from a submarine?
If your submarines don’t have VLS with correct dimensions that can accommodate the missile, forget it.
If however, your submarines have the correct dimension VLSs, then you need to develop technologies like nuclear ballistic missile submarines use to launch ICBMs. That is not easy either. When those missiles are launched from under water, they don’t use capsules. But the gas propulsion system is such that it does not allow the missile and the VLS containers to get wet. When such large missiles are being launched from under water, due to weight shifting problems subs would encounter sub’s balance may be compromised. Thus this will have to be addressed to keep the sub stable. This is achieved by filling the tube instantly to not allow any instability issues.
Conventional Submarine Torpedo tubes are predominantly 533mm in diameter and 6.4m to 7.6m long. Missile plus capsule diameter and length have to be smaller to fit. Ballistic missiles are too big to fit in these tubes. But cruise missiles can be built to be launched from these tubes.
Typhoon Block 1 is 610mm in diameter and 6.5m in length. Add the capsule too; it is far too big to fit.
Block 3 is ~8m long
Block 4 is 10m long (~938mm in diameter)
They definitely won’t fit.