What advantage or tactics have you used?

Two strategies to deal with it. Possibility 1 - go fast so whatver pops in doesnt get to shoot you much. Works well against Yavaris and anything counting on Blue / Black dice.

Option 2, leave a cloud of squadrons at the hperspace points to wait for them to pop in.

Depends on the respective fleet builds. I usually run whale + whale + [2xCR90B or whale]. If I see one ship across from me, pretty much regardless of what it is, if I think I can get there without too badly compromising my position to the ship in hyperspace, I charge in and try to maul it.

Don't usually get that opportunity, though. Realistically, three hyperspace points will be positioned in one of two ways. Either they're spread across the map, or clustered in the one area around their other ship. If they're spread across the map, there's only going to be one anywhere close to you, so just deploy as though the hyperspace ship is at that point. If they're all clustered in one area, play defense and refuse to fight there.

Hyperspace assault, if you counter it right, will either be a slaughter or a very delayed game, with climax at turn 5-6 (or not at all).

Broadly speaking, though, I just play the game assuming the hyperspace ship is at all three points simultaneously, in the worst possible orientation, speed, and timing. It's the disadvantage I've accepted in exchange for going first and not having to play Precision Strike against Yavaris B-wings or whatever.

I pick it sometimes, if I see my opponent doesn't have an asf is normally how I like to do it. Force him through maneuver to only have one decent assault jump, and activate yavaris first with your squadrons waiting for it to come in. Either he deploys to not be engaged and you gain more space, or yavaris gets them a double tap. I like to use wedge and dutch for yavaris duties as the can wipe multiple squadrons a turn if yavaris gets to trigger.

I am pretty relaxed about Hyperspace Assault. Effectively you are dividing your opponent's forces, and by placing the target locations within a VSD arc or two then you can predict where they might go. Just a case of mitigating against that risk, while seeking to close the range and pulverise my opponent's ships on the board while they are divided.

I chose it at Sullust against a Vic/GSD build with loads of TIES. I had 2xAF and Salvation build.

Just stayed away from his VIC and then just waited until he hyperspaced his Demolisher GSD in on turn 4. Hammered it and 4 squadrons of TIES for a few shield damage. VIC played no part. Not overly afraid of it.