Hello Joel,

  To manage the quoting process for bespoke projects in Odoo, consider the following approach:

  1. Utilize the Sales app to create detailed quotations. You can list all parts, their estimated costs, proposed suppliers, and lead times as individual products/services. For custom items, you can create them on-the-fly during the quotation process.

  2. For handling contingencies, create a specific product/service item labeled as "Contingency" with an estimated cost. This allows you to include it directly in your quotes without needing to raise an RFQ for it.

  3. Use the Projects app to manage and track the progress of your bespoke projects once the quote is accepted. This integration allows for seamless transition from quote to project management.

  4. For RFQs, the Purchase app can be used to manage RFQs for the parts and services you need from suppliers. While you wouldn't raise an RFQ for contingency costs, this app helps streamline the procurement process for other items.

For personalized assistance:
https://www.pragtech.co.in/contact-us-mql.html

Have you checked the Timesheet App? I think it covers what you are looking for. You can either charge for XX amount of hours of work. and if you exceed that time, you can make a new Extra hours and the equivlalent charge. 
Also there's the alternative of creating a service /hour quoted price and then check the amount of "used" hours.