Q: Using the same external hard drive to host a Time Machine partition + a test recovery partition: no longer possible?

In 10.7, I used to have one external hard drive with two partitions:

1) a Time Machine partition that I used to back up my internal hard drive;

2) another partition that I used once a month as a target partition to test the restoration of my Time Machine backup (because having a backup is a good first step, but regularly making sure it could be usable for a full recovery in case of a failure of my internal hard drive is important as well).

After upgrading to 10.9, my first backup restoration test failed with the error message "An error occurred while adding a recovery system to the destination disk." I found the following discussion:

https://discussions.apple.com/thread/4370294

which suggests that I need to make sure my external hard drive is formated using GUID and/or that I need to install 10.7 on the target drive. I checked in the Disk Utility, and indeed my external hard drive is formatted using Apple Partition Map rather than GUID.

I also found the following KB article:

http://support.apple.com/kb/HT5911

which suggests that, to be able to install 10.9 on the external hard drive, I need to configure it to have only one partition.

Can anyone confirm that it is no longer possible to perform a backup recovery test on the same external hard drive as the one hosting the Time Machine partition? Do I now need a second external hard drive if I want to perform such a restoration test?

Thanks in advance for your insights.