I'm trying to get a feel for just where Squadron operations hands things off the the incident staff or an exercise.
From what I have seen, the hosting unit creates the operations plan, sends it off to get approved & funded, appoints a project officer and disappears.
Consequently the first operational period is far, far more work than any that follow, with most of that landing on the Planning Section Chief, who is usually chief of nothing as the four unit leaders have never existed at anything smaller than a wing exercise as far as I know.
That sounds like a breakdown in including the planning section chief and the other branch directors from the beginning. From an ICS perspective, the incident staff should have been the ones to write the operations plan for the exercise to begin with. In a real-world operation, if your ICP is at the local Sheriff's office, that doesn't automatically make them the authors of the operations plan.
A good op plan is put together collectively by the branch directors and unit leaders, each contributing to their area of focus and then it is sent up to the incident commander and from there on wherever it needs to go.
The fact that a squadron operations officer & staff is writing a plan for an exercise simply because it's going to be at their squadron and then disappearing is very concerning and selfish on the part of the squadron. You write the plan to account for who is going to be in a given set of positions the same as you account for your other assets. Yes, the squadron should be consulted for concerns such as facilities, access if it's a controlled location, IT infrastructure, etc. but other than that it's the incident staff that runs the show.
Define operations plan in this context... If OPLAN means "here are our training objectives for this exercise", then it is completely reasonable for the sponsoring unit to define those.
If OPLAN means incident action plan, as in "here are our incident objectives for this operational period", that should be defined and completed by the incident command staff.
And, to further confuse things, our CAP-USAF folks here have us do an ICS201 to define the training mission objectives and attach it to the mission for approval. It works because I often happen to be both the IC and sponsoring ESO, but it could get super confusing if I wasn't. If I'm not the sponsoring unit but I am the IC, I still expect the unit to define their training objectives for me so that I can ensure game day meets those.
IMHO the activity planners and white cell should not be the ICP staff,
however that assumes there are enough people to segregate things.
There's not much point to the IC planning the scenarios and knowing
where the targets are, but sadly that's how it plays out all too often,
and even then people can't find things.