The way that the technology rules of 3P work are such that I tweak em here and there to prevent certain technologies from being realm-compatible, but here's a breakdown of what I've got so far.

The basic rules of technology in-realm are as follows:
-Electricity does not flow. Nervous systems and lightning appear to be exceptions.
-Electromagnetic radiation is only possible from infrared to the low end of UV. Gamma, X-ray, radio, microwave are all invalid and simply do not exist.
-Radioactive materials become inert very quickly, usually by following their standard progressions at an infinitely faster rate.
-Synthetic materials break down very quickly. For plastics this may mean that they grow brittle and break apart over a day or two. Kevlar and many resins may last up to a week. Many standard metals suffer increased oxidization, but this is not always prohibitive.
-Explosions cannot occur. All explosive materials will still burn, but no burn has any kind of kinetic energy.

The border between scientific and realm rulesets is very sudden. Space is either one or the other, never both, there is no middle ground.
Ferrous magnets function as per normal, despite the limitation on electricity.
Pneumatics and water-based hydraulics function as per normal.