Yeah true but we still don't know how much time has pass. There might be that the Time itself is not at a steady pace, Materusz left a clue to that in SNEE; Coordinates 987, the Broken Clock Room.
It does seem time doesn't "move at a steady pace," I'm well aware, but the Sanctuary might have been there as long as the Winter Palace has been there, or even longer, so that's a
considerable amount of time, adding more evidence to the possibility that the wall weakened over time, thus making it easier for the battering ram to break through the wall.
The leftmost room is dominated by a Grandfathers Clock. It has been torn apart, leaving only an empty shell. All the pieces are on the floor; weights, pendulum, clock itself, six cogs and the two hands. The clock itself is still making a ruckus!
That means Time is not kept at a steady pace.
How does that conclude to that at all? If you're referring to how the clock's still "making a ruckus," even though the clock's torn apart, then that kind of logic can lead me to say that the ambiance of any Location defines what's in it. It's an ambiance, I don't believe ambiances are vital to the plot, they're game mechanics.
The other part you quoted is from the Wiki, isn't it? That's all speculation, not
fact, speculation upon speculation makes matters worse.
Age is still a question to be interpreted. But look at how our time on Earth is measure: by the position of the Sun compared to where its light strikes the Earth. So far there is only Layer 2 that has something that even resembles a Sun, or a form of planetary baseline for measurement.
But so far we still don't know where each Room in all the SubNet related to the next Room due to the fact we still haven't seen a Map of the Submachine World. Until we have a baseline as to where each room relates to each other we can't denied the possibility that Time in each room are not all simultaneously.
We know for a fact that the Lighthouse and Root locations in SNEE are right next to each other, so the Root Locations must all work in the same timeline, being all in the Root, and same goes for the Lighthouse. Now I don't know if there's a Narnia-type deal, where time is valued differently in each area of the SubNet (i.e. the 742 years in Layer 7), so, of course, I can't tell you how time works, but if I could guess, there's two possibilities:
1) With the Theory that each Location sets its own Physics, that could lead to one saying it sets its own timeline as well.
2) Everywhere in the SubNet runs in the same timeline, which is why we're able to keep up with Mur in real-time.
But this is a tangent off the question at hand: How long has the notes from the end of Sub7 and beginning of Sub8 been waiting for us? How far ahead in the timeline is Mur and Liz from us, or are they keeping with us in real-time, as we seem to be doing?