how does the disruptor becon interact with tunnels?
not really, I have twiced used my elysians in appoc battles against this, it doesnt automatically effect you, only getting about half your squads, and thus if you can take it out on turn 2, it only effects half the squads in half your army, i.e about 1/4, since some deep strikes take place outside its sphere of control (notably support stuff) and some stuff comes on on your table edge (airplanes) and you can choose not to DS (do this with sentinels) then it hiots less than 1/4 of your army, I tend to drop 2 stormie squads in the first half, the first one goes for the beacon, if they deviate the second one will also, if they deviate then I will DS the sentinels, eventually you get serious AT weaponry in range, blow it up, and presto the remainder of your army is untouchedWell the way the rules puts it the controlling player of the device has complete control over where the troops go. Even though logically this makes no sence conserning tunnels. Obviously the units must come out one of the tunnels dug unless you have your troops carring shovels to improvise. (wow it is creepily quiet and lifeless in the library at school)
My cousin, my brothers, and i played a four way free for all last man standing appoc battle with each army being 4000 points. (o my god it took forever) and I borrowed my bros guard army and proxied it as drop guard while he used his old and long forgotten orks. My cousin took that blasted becon and used my dropping troops as a speed bump for the orks charging at him. It was horrible my entire army was crushed the turn they landed except for the squads I dropped in my deployment zone (massive table) and the ork deployment zone (crazy I know but it was the safest option). It was a great battle though. Ill post up a report over the weekend most likely.
But to the point of the topic. The beacon is extremely effective against a drop army. It can really throw a curve to your planns.