Agreed, the single build queues combined with long construction times is definitely the biggest issue as far as I'm concerned.
I suspect you're also correct that this is deliberate on the part of the devs, but I'm a bit baffled as to why. Given the game's pacing remains one of its single biggest critiques, you'd think they'd do more to address it.
Ah, well. For all its flaws, ISG is still a good game, and I'm looking forward to this DLC.