Information about the MT Prop Service Bulletin SB-30 is posted below in this thread. It seems the FAA has taken EASA's lead and determined the SB needs to be an Airworthiness Directive.
The latest version of the SB can be found on the MT Prop site
here
The Federal Aviation Administration (FAA) plans to issue the following AD effective 16 SEP 2022:
2022-18-02
If the link doesn't work, or you're not enamored with the new FAA Dynamic Regulatory System, I'll attach the proposed AD from the DRS site.