A few random thoughts:
These nice devices tend to be pivotal in my strategy, and I would hate to be vulnerable to these if I cannot respond myself. If the player using the Warp Openers/Closers is clever enough, and/or if there are only a few choke points, it is easy to close the wormholes as needed, thus preventing any enemy fleet from coming close to your worlds.
I have been trying the following strategy recently (*Winks at Primitive*), and I do believe it would work if done properly as you cannot ward yourself from Warp Openers/Closers without using these devices yourself. (Well, there is a facility protecting a system from warp opening/closing, but it cannot be built in a nebulae obviously) Lastly, it does give you the advantage of choosing your battles, allowing you to strike about anywhere without being too exposed to a retaliation if you protect your systems well.
So the Jenquai should have an easier access to these devices, while the research cost should be higher for the other races. This way, Jenquai would have an earlier access to these devices (if they go for it as soon as possible), but the early levels wouldn't be too efficient and they would be behind in other fields then.
Assuming the research cost is the same for them that in the vanilla game, you can reach Warp Openers/Warp Closers very early if you have enough space to expand. (Being boxed in a corner with two systems makes matter all the more complicated obviously) But then I tend to go overboard with technology as well. On the other hand, in the end game, they would have longer ranged openers, thus giving them an edge over the other races in this field, but a lesser advantage I guess. (It also depends on what assets the other races have, as there is quite a difference between having slightly stronger torpedoes and, say, the Religious trait.
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