Yes. In my case USCIS was really brutal. Made me wait 10 months before issuing a ridiculous RFE asking me to submit documents I already sent with my initial application. Then they waited until it was exactly one year to forward it to DOS.
honestly waiting 1,5 years at DOS stage is too much. You definitely need to sue them to get your decision. I was prepared to sue them. I know it is expensive but as a matter of principle they should not be doing this. Some people say “ oh well a waiver is a privilege not a right”. While it is true it’s up to DOS to grant it, they must decide within a reasonable amount of time. That is the law. Excessive delays are happening because these governments bureaucrats are not being challenged to follow the law.
as for the letter of representation, I am not sure. I guess it’s a different way to register form G-28 in their system.