Idea for making workflow rules run only in specifically cases ("options")

The following is not about asking for help, since it's working - but I am adding it here as it may inspire someone to use it for themselves.

I have some workflow rules that I want to run just on certain projects. There is nothing in particular that separates these projects from any other project where I do not want the rules to run (to save processing time).

What I have done is to create a custom field on the Project level of the type "Multi-Select Pick List".
In this list I have added various options, such as "Customer Price available in views", "Update related issues", etc.
In the workflow rule on the work item level that actually updates my custom field "Customer Price", I add a conditional (on to of any other conditional that may be there):
( Contains(ToString($Project.C_CustomSettings),"Customer Price available in views")
)
What this does it to make sure that the rule only runs if this option "Customer Price available in views" has been added to Custom Settings field in the project properties card to the project where the work item is.
This way of adding options is a pretty good way to have a set of business rules that should only run in specific cases and these cases are not easily handled by checking fields.
For Clarizen: it would be nice if options in the Multi-Select Pick List had a "display" value, such is "Customer Price available in views" and a data value such as "1" or "cp" and make it possible to check these values without "contains" and "tostring"