This setting under Advanced Options allows you to define a default merchant account to be used for eCommerce actions. This default merchant account only applies to eCommerce transactions that are executed within Memberium. It does not control which merchant account is used for transactions that happen within Infusionsoft itself.
This setting allows you to control how shortcodes are processed for OptimizePress 2.0’s (OP2) drag and drop design pages. You can choose between individual element processing, or more flexible full page processing.