From my experience there is one key fundamental about military leave. Straight from the JAG office is that any member is NOT REQUIRED to give orders, or any official document to their employers period. If your CP or any individual mandates you give them orders or any kind of paperwork, respectfully refuse and let them know you are not required to. I'm sure if you give advance notice none of this should be an issue.
That being said, usually it's in the best interest of the pilot to email their chief pilot a formal email stating the days they have to report for duty, or any extra mil days. This goes especially for the military pilots because usually they are present for more than just a weekend. Envoy, or any airline does not need to know the yearly drill calendar, nor receive copies of orders which have PII on them.
Best advice is send a formal email asking to be removed by scheduling, and give as much notice as you can. Airlines are getting brutal with mil leave, especially because of staffing. I don't really know much about the whole keeping travel benefits, although it seems ridiculous you can't continue to use them (even though you're still holding a seniority.)