I'm a big fan of playing defensive in Stellaris, managing chokepoints and letting others break their fleets on my bulwark of defense platforms and network of starbases. I would love a technology tree to further limit access to my empire. Technology to close the existing wormholes or perhaps re-direct them to another system, dumping them into the exterior bulwark of defenses. The ability to lock L-Gates in the same way that Gateways are managed during warfare. Delving deeper into this idea; the ability to manage hyperlanes, blocking or restricting travel to a certain entrypoint by-way of a massive FTL inhibitor that requires a large number of your defense platform slots. The introduction of a megastructure (along the lines of gateway's and habitats) that you can deploy to the hyperlane direclty, which can restrict travel even slightly (requiring you to send through smaller groupings of ships at a time), but at the same time reduce your sensor range around that quadrant (unless of course you have a sensor array or allies on the other end). Given enough intel on an empire, you can begin a special mission to gain clearance codes, which allow you to bypass their blocks and also use their gateways (empires would be notified and need to do a one month society research task to change their codes). Even introducing more defensive based technologies, attached to starbases or planets, allowing the creation of planetary defense fleets that can stall for time, planetary ion cannons that can weaken invading armies or delay a planet cracker.
I think overall this would increase the viability of playing tall, and with the addition of harder crises, the viability of surviving when they spawn just at the edge of your borders. Again that's also applicable to Khan's, Fallen Empires, and advanced start empires that are immediately hostile.
I think overall this would increase the viability of playing tall, and with the addition of harder crises, the viability of surviving when they spawn just at the edge of your borders. Again that's also applicable to Khan's, Fallen Empires, and advanced start empires that are immediately hostile.