Power HA 7 repository disk unmirrored?

hi guys,

I don't like the new concept of the power ha 7 cluster with the repository disk and the internal solidb, I really would like to mirror this disk, but the "IBM PowerHA SystemMirror 7.1 for AIX" redbook says, normal lvm operations should not be performed on this disk.
even mirroring the vg wont use much, because the hdisk device is configured directly to power ha, and not the vg.

well the cluster will run without the repository, and a new one can be specified, but with a downtime I guess, but that's not what I want for my clusters. no changes to the cluster can be made without it, even such as start/stop I guess.

everything is mirrored, a downtime of a whole storage side was no problem till now.
any thoughts on this? has anyone experienced the behaviour of a cluster in this situation?
of course I will test this on my own too, but I have no test system yet

cheers funksen