Incremental backup recoveries when backups are performed on different media

Hi,
We are using a backup solution which backups Oracle Database with RMAN, directly to tape.
It uses scripts such like these:

RUN {
shutdown immediate;
startup mount;
ALLOCATE CHANNEL CH1 TYPE 'SBT_TAPE';
BACKUP
incremental level 0
 FORMAT 'BackupIncrementalCloseNoarc_%d_%s_%T'
 DATABASE
;
RELEASE CHANNEL CH1;
alter database open;
}

and

RUN {
shutdown immediate;
startup mount;
ALLOCATE CHANNEL CH1 TYPE 'SBT_TAPE';
BACKUP
incremental level 1
 FORMAT 'BackupIncrementalCloseNoarc_%d_%s_%T'
 DATABASE
;
RELEASE CHANNEL CH1;
alter database open;
}


And we also have databases that backup using this scripts:

run {
ALLOCATE CHANNEL t1 TYPE 'SBT_TAPE';
backup
incremental level = 1
cumulative
format  BackupOpenCumulative_Incremental_Level_1_%d_%s_%T  database plus archive log delete all input;