I used https://make.powerapps.com to customize the Account|Sales Insights form.
I added the customizations to a solution.
The Sales Trial environment https://haddley-sales-trial.crm.dynamics.com
By default the Accounts page in the Sales app displays the Account|My Active Accounts view
Clicking on an Account in the Account|My Active Accounts view opens the Account|Sales Insights Form
To customize the "Sales Insights" form I navigated to https://make.powerapps.com and selected the the "Sales Trial" environment
I created a "Sales Customizations" solution
I create a new publisher (Neil Haddley)
I added my email address
I clicked the Create button to create the new solution
I wanted to add an existing table
I added the (existing) Account table
I clicked the "select objects" link
I selected the "Sales Insights" form and clicked the Add button
I deleted the Fax element from the Account|Sales Insights form
I deleted the Ticker Symbols element from the Account|Sales Insights form
I deleted the Shipping section from the Details tab of the Account|Sales Insights form
I deleted the Number of Employees element from the Account|Sales Insights form
I saved and published the changes
I returned to the Sales App https://haddley-sales-trial.crm.dynamics.com to review the changes