I'm not a Marine Architect... A former colleague in what was once ILS(N) was a Senior Stores Officer on on of them and he described the vaults as being in the same league as the BoE vaults.
Also, the 'Bomb Shops' on the carriers would need to be modified along the same lines...
Two carriers plus six RFA conversions? That's several hundreds of millions, as a guesstimate... for a very dubious tactical, not strategic, capability.
You mentioned the HAS vaults... what about the SSA? ...and the Forward Ops locations, e.g., Lossie...? And the 'Depot', not AWE? And the convoys? You can't send those things 'Next Day' by Yodel! Other distribution agents are available. The costs just keep going up... and up... and up..............
I look forward to having a look at the paper.