When working with partners, I find customizing is almost imperative. Invariably the customer has this feature, this product and many other things which must be tied together to make the ultimate install.
You might find these links helpful when you customize Lotus Symphony.
This article list the benefits
of upgrading to Lotus Symphony 3 in the Lotus Notes client and provides
a link to the detailed instructions.
Preference Customization is a
new capability added in Lotus Symphony 3.0 . Preference
Customization can help a System Administrator customize Lotus Symphony
before deploying it to the enterprise. This article shows how to do
preference customization by updating the Symphony installation package.
Installing Symphony on a USB drive
These are in addition to the great links already in the Enablement Roadmap
IBM Collaboration Solutions Technical Enablement
Matching: custom X