Hello.
I tested new TOAST (https://github.com/postgrespro/postgres/tree/jsonb_toaster) mechanism for jsonb data types. Version (15.1 (Debian 15.1-1.pgdg110+1), server 15beta1). Test table has 6 columns which has jsonb data type.
I was inserting a "large" amount of data (over 1 million) and noticed the session “eats up” the entire RAM. (I saw it in Zabbix monitoring system)

Also, each I run update statement I get the following error:

WARNING: terminating connection because of crash of another server process
DETAIL: The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory.
HINT: In a moment you should be able to reconnect to the database and repeat your command.
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Succeeded.