Observed that, cross-engine joins on text column is not supported.
Can we fix this?

MariaDB [suresh]> create table foo5 (a text );
Query OK, 0 rows affected (0.006 sec)
MariaDB [suresh]> create table bar5 (a text ) engine=columnstore;
Query OK, 0 rows affected (0.220 sec)
MariaDB [suresh]> select * from foo5 where exists ( select 1 from bar5 where foo5.a=bar5.a);
ERROR 1815 (HY000): Internal error: VARBINARY/BLOB in join is not supported.
MariaDB [suresh]> select * from foo5, bar5 where foo5.a=bar5.a;
ERROR 1815 (HY000): Internal error: VARBINARY/BLOB in join is not supported.

[root@test001 ~]# rpm -qa|grep -i column
MariaDB-columnstore-engine-10.6.7_3_6.2.3-1.el7_9.x86_64
[root@test001 ~]# rpm -qa|grep -i mariadb
MariaDB-server-10.6.7_3-1.el7_9.x86_64