Alright, another idea I had for a method to implement mine laying is as follows:

The miner ship is a normal frigate.  Mines are a special type of strikecraft.  When you place a mine, the phase engines on the miner ship are disabled (to avoid the problem I had before where the miner ship would drag the mines along with it through phase space.)  If all the mines of the miner ship are destroyed, the miner ships phase engines are brought back online.

To implement this, I gave the miner ship an aura buff that places a buff on its strikecraft every second.  The buff that is placed on the strikecraft then turns around and places a buff on the miner ship.  The buff on the miner ship disables the miner ship's phase engines.  That buff on the miner ship has a finish condition that if the mine no longer has the first buff, the miner ship buff goes away.  The miner ship buff stacks, so multiple mines should disable the phase engines properly.

The problem I am having is this:  I cannot get the first buff (on the mine) to place the second buff on the miner ship.  I tried using ApplyBuffToTargetsLinked and ApplyBuffToLastSpawnerWithTravelNoFilterNoRange (from the modifier sticky in this forum), but neither of them worked.  Has anyone been able to get that basic functionality to work in their mods?

Thanks for the help.