Every change that you make to a FlexJob on the fly is automatically saved inside the customization.

To preview how the job is going to look to your customer on the proposal simply open the View/Edit on any FlexJob inside the proposal builder app. Customer-facing elements of customization are arranged in the same order as they would show up on the presentation.

This view is available before you add or recommend a FlexJob on the proposal and, then, from inside the proposal preview on Accessories and Installation Items pages.