well from what i gather from my own experiments by baking it i can issue orders to units during the deploy phase that are then permanent each time the scenario is played
by setting up an FO with LOS on the areas i want to put Indi FS on i can then setup firemissions at 1min , 2mins , 5mins 10 and 15mins into the mission just by using the available fire mission commands. This gives me kinda 'scripted' ai fire missions to work in with the timing for an enemy ai assault or counterattack etc. (linked to timing of reinforcements and leave before/after commands)
seems to work fairly well the only limiting factor this way is that i cannot get AI to call fire missions after 15mins into the scenario...
I woulda thought if tubes were available and an FO had LOS on a taret the ai would do this automttically but it doesnt seem to .