What do the "Spread Angle" and "Canopy Max Rotation Rate" for parachutes do?

[Jestersage]

As topic. My guess with Spread Angle is how far apart the rope connecting the parachute to the container spread. I only read one unofficial theory about Canopy Max Rotation rate.

[Lego_Prodigy]

Spread angle is probably how much the parachutes spread out upon activating. Canopy max rotation is probably how far the parachutes can rotate, like a limitation to rotations so that it don't get tangled (which I hope is wrong). Thats just my thoughts though.

Tbh, I didnt even know those were things, so I wouldn't worry about it too much.

[Zeiss Ikon]

Spread angle is exactly what you think it is: with the limitation that it only affects parachutes installed in symmetry sets.  So, if I use the 3-symmetry setting to put three Mk. 2 radial parachutes on a Mk. 1-3 Command Pod, I can adjust the Spread Angle for the parachutes to determine how much separation the canopies have when deployed.

So far, I don't see any indication in Google that anyone knows what the Canopy Max Rotation Rate does.  From the name, it seems it would be related to the tendency of some parachutes to spin when deployed at high speed, which could affect your game performance (causing a temporary slowdown as the CPU deals with rotating the canopy skin).

Edit to add: I see the Max Canopy Rotation Rate in the parachute settings in VAB, but I don't see it on parachutes on vessels already in flight.  Since I'm still running 1.4.1/MH, I presume this was new for 1.4 or 1.4.1, but I don't recall seeing the canopies rotate on recoveries since upgrading to 1.4.1.

Edited April 1, 2018 by Zeiss Ikon

[blakemw]

Spread Angle (when used in symmetry) actually increases parachute efficiency, 2 radial chutes with max spread angle are about as effective a 3 with 0 spread angle. If you're using radial chutes it's a free optimization to max it.