I'd like to track overhead quoting and manual project setup/admin time based on the inquiries that I respond to or events that happen as clients move through the pipeline.

I already have an internal Client/Project system set up for tracking overhead tasks, so:

an automation such as the following could automate this:

When Opportunity Enters Stage (such as "Quote Sent" or "Launch Project")

add X amount of time to a specified Client and Project.

Potentially this could track time for individual clients/projects with a more detailed setup as well.