Here are some instructions that might be easier to follow than the manual, because they are specifically for creating multi-boot Protogo devices:
Making a custom profile using TechTool Protogo:
1. Click the ‘New’ button.
2. Double click the Untitled Configuration that appears, or select it and press Edit.
3. The new profile will already have the Basic profile included, click Add Volume to add a second profile.
Change the ‘System’ drop-down menu to reflect the profile you want to add.
4. Repeat this process, adding the profiles for your situation.
5. Name the profile, and click Save.
Now, you can build the Protogo device, and it will include one partition for each profile that you have included.
Note that it can be convenient to add the Basic profile last, so that it gets any remaining space on the device. Also, remember that PowerPC Macs only boot using FireWire devices. If you include the PowerPC profile on a device that is USB only, it will only boot Intel Macs that support 10.5.8.