CFZ

Cossie, Seeing as though I actually build shocks all the time for my late models, I know a little more than some about shocks. Yes Nitrogen gas is used to put pressure into the shock to prevent hysteresis. I do not know anything about RC cars.....

The oil is not transferred into heat, There is no warm up period of a shock or anything like that. It is restricted through the valving of the shock. The oil goes through the piston of the shock and is restricted through the stacks of shims. the more shims the less they flex making the valving stiffer. Now this is done on both sides of the piston to adjust rebound on one side and compression on the other. The shock oil generally does not change color. There are different weight oils depending on valving of the shock, but most racers in my experience uses a very lightweight shock oil and adjusts valving through the shims. It is actually the opposite of what you are saying, heat is one of its enemies.

When I say changing the valving of a shock I dont literally mean changing out the valves like you would in an engine. By valving I mean changing the dynamics of the shock through the shim stack. Which is a common term.

When you use shocks for a long period of time the oil does get inconsistent, but this is because of few things, When racing for long periods of time they obviously heat up like any hydrolic system.
Twin-tube shocks are even worse off because the nitrogen and the shock oil physically mixes itself up causing cavitation.

The reason why shocks blow is because the seals and o-rings eventually wear out. Or bottoming out the shocks.

Signs on a twin tube shock
-leaking
Signs from a monotube
-leaking
-the shaft does not push itself back out when compressed (gas is in a seperate chamber so the secondary piston seal is blown)

I dont know where you are getting your information from but either Im not understanding you (which is likely the case) or you have some weird shock made but some kind of mad scientist.

From what you are saying warn out oil is the cause of blown shocks. Which does not make much sense. From our experience oil temps going up does increase inconsistencies but nothing makes it blow. And like I said before the stiffer spring minimizes movement in the shock, A soft spring will obviously increase movement, but the speed of the movement in a stiffer rate spring will be increased.