Thanks Steven,
Evidently my second email got lost somewhere along the way- what you'relooking for is an extension called 'pgrowlocks': https://www.postgresql.org/docs/10/static/pgrowlocks.html My prior email on that subject is here: https://www.postgresql.org/message-id/20180315220512.GV2416%40tamriel.snowman.net
I’ll look into that as soon after next week. Best, /eno