RMAN backup maintenance

We have RMAN backups scheduled to run incremental level 0 full on Sundays and incremental level 1 on weekdays. The generic RMAN backup script is as follows:
{
backup
 incremental level $LEVEL
 database plus archivelog
 delete input filesperset 1;
 release channel d1;
}

We also run a maintenance script to clear the records in recovery catalog. The contents of the maintenance script are as follows:

CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 21 DAYS;
CONFIGURE BACKUP OPTIMIZATION OFF;
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F';
ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE disk;
CROSSCHECK BACKUP;
REPORT OBSOLETE RECOVERY WINDOW OF 21 DAYS;