Generally yeah, but the value of it dives of the cliff in some cases, compared to the hassle it introduces. Lets say you create a encrypted LUKS partition with a 32 character password. Would it be more secure by nesting 3 more encrypted LUKS partitions inside of that one, with each having different 32 character passwords? Yeah sure, but you're already pretty secure with just one as long as the password is good.

In the case I mentioned, adding TLS certificates to something that is already signed in a similar way that TLS would do, would add nothing in terms of security, but would add additional privacy.