Thank you for expressing your opinion.Erm, seabed argument is mostly for conventional subs. Nuclear submarines normally can't lie on the bottom, unless specifically designed for it.
For nuclear submarines, as a rule of thumb, deep water=good.
Thus there are already absolutely ideal positions right behind 1st Chain - an absolutely enormous swatch of sea no ASW can properly lock, yet protected by that chain from any consistent Chinese ASW, yet covered by lots of convenient islands(often mountainous) from too early detection of launch, yet almost always with enough weather patches to interfere with space-based IR/Optical observation and early warning assets.
Importantly, key targets for immediate suppression (political centers, C&C, etc) are either very close(and there are better means to strike them compared to ballistic missiles), or are relatively far from SCS - i.e. other strike locations are more advantageous from this point of view, too.
SCS is by now the main hub of Chinese naval activity(not even one of anymore), the bastion of Chinese sea deterrent, and a starting point of PLAN SSN deployments.
USN SSBNs don't need to be a reason...
But sorry I still don't buy your argument.
Only thing is time, we will have to wait and see what happen next.