The best practice for identifying which stage in the sales process the industry standard due-diligence should be embedded is to develop a process map as a base, work with stakeholders to understand the trigger point, and locate the stage. This practice helps to:
* Develop a process map as a base: This provides a visual representation of the sales process, showing the steps, inputs, outputs, roles, and decisions involved in each stage.
* Work with stakeholders to understand the trigger point: This helps to elicit feedback and insights from the stakeholders who are familiar with or affected by the sales process, and identify when or why the industry standard due-diligence is needed or required.
* Locate the stage: This helps to determine where in the sales process the industry standard due-diligence should be embedded, based on the trigger point and the business logic. References:
https://trailhead.salesforce.com/en/content/learn/modules/business-analysis-process-mapping/create-a-proc

The action that the business analyst should take to quickly introduce new functionality to impress the customer is to demo standard features and elicit feedback from the customer. Demoing standard features means showing the customer how Sales Cloud can provide out-of-the-box functionality that meets their needs or expectations without requiring extensive customization or development. Eliciting feedback means asking the customer for their opinions or suggestions on how Sales Cloud can improve their sales process or performance. Demoing standard features and eliciting feedback helps to quickly introduce new functionality to impress the customer by demonstrating the value and benefits of Sales Cloud, as well as engaging and involving the customer in the solution design and delivery. References:
https://trailhead.salesforce.com/content/learn/modules/salesforce-business-analyst-certification-prep/customer-di

This answer states that reviewing the services team's goals, initiatives, strategies, and obstacles is what the BA should do to determine if the current solution of implementing an Experience Site that allows customers to view Knowledge articles and submit cases is adding value to UC's business. Goals are what the services team wants to achieve or accomplish in terms of business outcomes or benefits. Initiatives are what the services team plans to do or implement to achieve their goals. Strategies are how the services team executes or delivers their initiatives. Obstacles are what prevents or hinders the services team from achieving their goals, implementing their initiatives, or executing their strategies. Reviewing the services team's goals, initiatives, strategies, and obstacles means that the BA analyzes and documents these elements related to implementing an Experience Site that allows customers to view Knowledge articles and submit cases.
Reviewing the services team's goals, initiatives, strategies, and obstacles is what the BA should do to determine if the current solution is adding value to UC's business because it helps the BA to measure and evaluate the performance and impact of the current solution against these elements. References:
https://trailhead.salesforce.com/en/content/learn/modules/salesforce-business-analyst-quick-look/use- stakeholder-engagement-skills

Explanation
The best practice for preventing a session from being derailed by an off-topic stakeholder is to use a "parking lot" technique. A parking lot is a list of topics or issues that are not relevant to the current session but may need further discussion or resolution later. The BA should add the stakeholder's concerns to a parking lot for further discussion, and acknowledge that they are important but out of scope for the current session. This way, the BA can keep the session focused on the onboarding process and avoid wasting time or losing engagement from other stakeholders.
References:https://trailhead.salesforce.com/en/content/learn/modules/business-analysis-process-mapping/plan-an