The Cs do mention the 4th dimension as an in-out and not being able to tell left from right (curved roads looks straight). It's like the stuff on one side can be lifted out of the page and be seen on the other side too. I saw it once in a physics blog described as not being able to tie your shoes. It relates I think to the Lethbridge pentagons in third density looking like triangles in 4th thing since a regular pentagon has a line segment on one side and a point on the other.
I was thinking more in line with:
4 spatial dimensions like (+/- x, +/- y, +/- z, +/- r), where last one (+/- r) tells us how far something from the 'edge' is.
E.g. Our normal (+ r) would tell us how far 'outside' something is ("out" part of duality) and (- r) how far 'inside' ("in" part of duality) from the 'edge' (reference point), indicating decoupling from other 3 spatial dimensions, i.e. (in/out) would be 'equal' to other 3, usually used spatial dimensions (x,y,z).
In the limit where reference 'body' becomes a point (no 'inside' part), this dimension would become what we usually call "radial" one, mathematical 'r' without its negative part.
Thinking about 2D time disk + 4D space hypersphere you mentioned above and our 4-vectors and their opposite signs of its spatial and temporal parts, it almost looks like that you end up with a boundary of 3D sphere and complex time, but not inside the sphere but outside of it. Like you got a spatial sphere and everything outside of it, but not its interior.
If that's the case, would a 'name' vacuum maybe be suitable for this interior that has 'run away' from our perception?
You do get a complex spacetime domain dual light cone structure going indefinitely in opposite time-like directions which Ark has recently related to the two universes (matter & antimatter) which related to the lost in the Bermuda triangle ideas.
Antimatter with same sign of mass and real mass, same as matter, doesn't sound like 'true' antimatter to me. Since we already know about dual part (counterpart) of matter (particles), which is wave, could wavicles that Ark mentioned be 'true antimatter' to our matter?
Regarding time, we globally perceive it in relation to 'our position' in Universe (probably cyclically), closest reference points being Sol and Luna. Maybe that's the way to differentiate between 'past' and 'future' time dimensions, one is in relation to 'next-to-us' body 'above' and other in relation to body 'bellow' in the Ray of Creation?
E.g. From relation to Sol, we get solar year (1 round around it) and solar day (1 round around us compared to sun), and from relation to Luna we get lunar 'year' (1 round around us; our month) and lunar 'day' (1 round around the moon in reference to Earth, which would again be our month).
I would somehow expect that maybe ratios among different part of the cycles (e.g. year-day) show some pattern, maybe like some nice sequence (Fibonacci comes to mind), and that from that we might get an indication where we are 'on the grand cycle' of things. Like, ratio between lunar year and lunar day is 1, corresponding to F1 and/or F2 in Fibonacci sequence, and ratio between solar year and day is ~365 which is pretty close to F14 (377).
Does this make any sense?