SharePoint Designer 2013 Workflow: Reading Check In comment, programmatic elevation of permissions, alternatives?

I’ve created a workflow for a review process, that copies a file into a “working” library, takes the check-in comment through Rest API (with elevated permissions and full appinv access) and then saves it as part of the comments history log (Among many other things, but this is the problem specifically).

This has been working great and dandy UNTIL, I’ve packaged it and need to deploy as template, I’ve noticed that the workflow ID changes and this means that each time a new site (Project site) is created, needs to send a mail/flag somehow someone from IT to elevate permissions in the appinv for that specific site collection (manual Admin appinv authorization).

I know how to do all of the above very well, with the exception that it’s not going to work for a massive deployment. With all of the above said this are the questions:

  • Can I get the Check In Comment through a SharePoint Designer 2010 or 2013 in any other way that does not mean using Rest API?
  • Is it possible to programmatically elevate permissions? I found this resource but I can’t seem to make anything out of that, it’s a powershell and should be run on a timer? http://parlaesolutions.com/blogs/Programmatically-Enable-Trust-for-Built-In-Workflow-App
  • Any other ideas?

My first suggestion was, could we create a new field and add the comment there followed by a no, it has to be the Check In Comment sadly.

Thank you!