Lightning Experience
Warning: Desktop and lightning experiences cannot be used simultaneously. If you activate the lightning experience on your SFDC instance, pay attention to migrate your CPQ managed package as well.
PROS Quote Layout
In order to use CPQ with the Lightning experience, you have to customize the PROS Quote object (Setup/Object Manager/PROS Quote)
In the Buttons, Links and Actions part, edit the view and select the Standard Salesforce.com Page
Then, edit the Quote layout that you are using to display the Quote Content button
The Quote Content button has to be added in the “Salesforce1 and Lightning Experience” part.
You are now able to open the PROS Quote with the Lightning Experience
To open the PROS quote, click on the Quote Content button:
Screen Mode (Custom Settings)
Currently the Screen Mode defined in the Custom Settings is not taken into account when using the Lightning UI.