SharePoint Workflow - set workflow permissions dynamically

Hi!

Is it possible to dynamically set workflow permissions on current site (spweb) using REST or CSOM/JSOM?

I'm talking about enabling APP STEP in SharePoint Workflow 2013:

- enable feature "Workflows can use app permissions"

- granting full control permission to a workflow using "/_layouts/15/appinv.aspx. "

This is possible on On-premise using code (http://parlaesolutions.com/blogs/Programmatically-Enable-Trust-for-Built-In-Workflow-App) but I have not yet found a workable solution for SharePoint Online.

I need this because I have a service that dynamically creates a site from template and has some workflow attached which should have elevated permissions.

Any idea?