I had posted this in the open in the hope of attracting both the level of support and any pitfalls.
So far, I've thought of this so far:
There could two, or even three marks for the post.
MK I would cost around the cost around 3k knowledge, and would cloak nearby units while the unit itself is visible. However, unlike turrets, when the comm station on the planet it is on is destroyed, it too, should be destroyed. This I think could work even if the MK II and or III version is abandoned.
MK II are an optional idea. For the cost of around 3k knowledge, this station would be alike to the previous post except it would remain even if the comm station it was on was destroyed...but it would still need supply. So you are paying a premium to keep the factory IV, etc hidden.
MK III's could go a step further and have the post itself be hidden. In return for this neigh invulnerability of the factory IV if you keep the post in supply you are paying a whopping 4k knowledge, or 10k total knowledge...remember an enclave which needs no factory costs 14k...so its an alternative form of fail safe.