One suggested mitigative strategy against Logjam-related attacks on SSH is to generate custom SSH Diffie-Hellman groups using something like (the below being for OpenSSH)
ssh-keygen -G moduli-2048.candidates -b 2048 ssh-keygen -T moduli-2048 -f moduli-2048.candidates
followed by replacing the system-wide moduli file with the output file
ssh-keygen -G is used to generate candidate DH-GEX primes, and
ssh-keygen -T to test the generated candidates for safety.)
This is pretty clearly a reasonable thing to do on SSH servers that otherwise would be using well-known groups that lend themselves well to precomputation, but are there any security benefits to deploying custom SSH DH groups onto client-only systems? (That is, systems that connect to SSH servers, but never act as an SSH server themselves.)
I am primarily interested in answers relating to OpenSSH on Linux, but more generic answers would be appreciated as well.