For User Acceptance Testing (UAT) to be efficient, it's crucial to have clear and agreed-upon acceptance criteria with the customer. This ensures that both parties have a mutual understanding of what constitutes a successful test outcome. Defining these criteria upfront helps streamline the testing process, as it focuses efforts on verifying that the system meets the business requirements and expectations. While the specific document reference for this answer isn't available in the provided Salesforce Revenue Cloud documents, this approach is a widely recognized best practice in UAT planning and execution in software development and implementation projects.

A project manager is the role that is primarily responsible for project success, especially when an escalation on a Revenue Cloud project happens. A project manager oversees the end-to-end delivery of a Salesforce project, ensuring that the project is delivered within scope, budget, and timeline. A project manager also coordinates the communication and collaboration among the project team, the customer, and other stakeholders, as well as manages the risks, issues, and changes that may arise during the project lifecycle. A project manager is the first point of contact for any escalation on a Revenue Cloud project, and is expected to resolve the escalation promptly and effectively, by applying the appropriate escalation management process and involving the relevant parties. A project manager also monitors and reports on the project progress, quality, and satisfaction, and ensures that the project meets the customer's expectations and business objectives. 1234 References:
* 1: Your Guide to Salesforce Roles & Responsibilities
* 2: Salesforce Introduces Revenue Cloud to Help Businesses Accelerate Revenue Growth Across Any Channel
* 3: Marketing Cloud Consultant Job Description
* 4: What Is Salesforce Revenue Cloud?

The three common CPQ design mistakes to avoid while implementing CPQ for your customer are:
A) Using price book entries to handle attribute based variations instead of lookup price rules: Price book entries are not designed to handle attribute-based variations. Instead, lookup price rules should be used. These rules allow you to adjust pricing based on specific product attributes, providing more flexibility and accuracy1.
C) Creating process builders and flows to pass data between fields instead of using twin field mapping: Process builders and flows can be complex and difficult to maintain. Instead, twin field mapping should be used. This feature allows you to map fields between objects, ensuring data consistency and reducing the need for custom code1.
D) Writing customizations for product selection or validation instead of using option constraints, product rules, and bundles: Customizations can be time-consuming and costly to implement and maintain. Instead, Salesforce CPQ provides built-in features like option constraints, product rules, and bundles that can handle product selection and validation. These features are designed to enforce business rules and ensure that only valid product combinations are selected1.
Reference:
https://inspireplanner.com/blog/5-common-salesforce-cpq-implementation-challenges-and-how-to-avoid-them/