Now that all DH implementations support ephemeral key generation triggeredAs noted previously, maybe you can consider switching to ffdhe3072 here.
by passing a ->key_size of zero to ->set_secret(), it's certainly
worthwhile to build upon the testmgr's do_test_kpp() ->genkey facility to
test it.
Add two ->genkey DH test vectors to the testmgr, one for the RFC 7919
ffdhe2048 group and another one for the RFC 3526 modp2048 group.