Things are still unclear....as of now.....Let me start inserting HSN summary from May GSTR-1 onwards as the correct practice and lets see any Notice comes for April GSTR-1....Since this mistake was truly unintentional, i hope GST Dept should be lenient in this regard or may allow us to revise the GSTR-1 April 2021 if they have any such powers.....Lets wait and watch