Unfortunately, the only processing time reported for MSC is for "All field offices", which is currently at 31 months. It really depends on how fast your local office is at scheduling ROC interviews, which are quite low on the priority list.
I entered my receipt date (also June 2020) on the USCIS website to see when an inquiry can be made and they said October 2023, which is ridiculous.
To be honest, the only reason I am done with USCIS is that I applied for citizenship and they processed my ROC at the same time.