after adding this most of metallurgy 4's metals do get things like gears and dust but don't get plate support besides for 2 items osmium and electrum.

not sure of another way to get the plates in if there is a way.

just remembered that metallurgy 4 has tinkers integration so I guess its seeing those and not adding the plates due to them being there in a way. so not sure if there is a way to force them then.

edit
so after adding in tinkers construct your mod added the plates which is strange