Is it possible to set Original Estimate using Project Automation in Legacy Mode?

[Clayton Taylor]

I am trying to automate Original Estimate / Remaining Estimate using Project Automation and it appears that there are some strange restrictions when "Legacy Mode" is applied in the Time Tracking settings.

I work for a large company and our Jira admins don't want to disable Legacy Mode because of how many projects/teams it would affect. With that as a constraint, I can't figure out how to set Original Estimate or Remaining Estimate when an issue is created. I have tried rules that set either field as well as one that sets both fields in the same action, but in all three cases I receive the following error in the Audit Log for the rule: "Setting both Original and Remaining Estimate is not supported in Legacy Mode. (timetracking)".

Is this even possible in Legacy Mode or am I wasting my time? Any help would be much appreciated.