Starting HDR and using only level-0 backup vs (currently not implemented) using level-0 with incremental backups

For physical restore secondary of HDR, level-0 must be using. If you are using incremental backups from primary for physical restore on secondary, you get the error on secondary IDS in online.log:

...
11:55:36 DR: new type = secondary, primary server name = hdr_lo
11:55:36 DR: Trying to connect to primary server = hdr_lo
11:55:38 DR: Secondary server restored from a non level-0 archive - aborting
11:55:39 IBM Informix Dynamic Server Stopped.
...

Why IBM does not fix this behavior for possibility using incremental backups for physical restore secondary HDR?