This might be highly controversial, but I think the whole concept of allowing players to spawn portals on a whim is fundamentally broken as a design premise. It undermines too much of the staple dynamics of established shooter games: it undermines predictability, accountability and pacing. It also heightens the design pressure of ugly emergent mechanics like corner peeking. Furthermore, it makes geometry that can be traveled from and to unusually appealing to stick to, reducing the expressiveness of different maps. If the game is going to be reworked entirely, I would strongly suggest to reconsider the whole gimmick.