1. Sir, yes in my opinion, such employees will be covered.
2. In case there are any contractor employees who are permanently posted in non-implemented areas for more than 7 months, you can seek their exemption from coverage under ESI Act, 1948 and rules/regulations framed thereunder.
3. If you have any doubt, I think, it will be safe to consult in writing to the appropriate Region/Sub Regional Office of ESIC to which your unit is attached.