On Pub and Sub:
------------------
DO $$
BEGIN
    EXECUTE 'CREATE TYPE ri_n0 AS (f text)';
    FOR i IN 1..25 LOOP            -- levels knob
        EXECUTE format('CREATE TYPE ri_n%s AS (f ri_n%s)', i, i - 1);
    END LOOP;
END $$;

CREATE TABLE t (k ri_n25 PRIMARY KEY);

Pub:
-----
CREATE PUBLICATION pub1 FOR ALL TABLES;

Sub:
-----
(Use destination as 'table'; 'all'/'log' may end up consuming too much memory to dump such a huge RI, and thus the CLT-related problem may be hidden.)
CREATE SUBSCRIPTION sub1 CONNECTION '...' PUBLICATION pub1 WITH(CONFLICT_LOG_DESTINATION='table');


Pub:
-----
DO $$
DECLARE r text := format('ROW(%L)::ri_n0', repeat('"', 10));
BEGIN
    FOR i IN 1..25 LOOP
        r := format('ROW(%s)::ri_n%s', r, i);
    END LOOP;
    EXECUTE format('INSERT INTO t VALUES (%s)', r);
END $$;

Sub:
-----
--wait for data to be replicated, check stored length:
SELECT pg_column_size(k) FROM t;

Sub:
-----
DELETE FROM t;

Pub (to reproduce delete_missing conflict):
-----
DELETE FROM t;      -- subscriber now errors and retries in a loop