According to BI wiki, random operator can be used to create a random perlin noise with seed random [x, y] syntax, but it doesn't in game.

https://community.bistudio.com/wiki/random

https://imgur.com/Bp0s4CE
https://imgur.com/jSEGhqa

1st image source code:

for "_i" from 0 to 1 step 0.001 do {
	diag_log str [_i, 1 random [_i, 0.5]];
};

2nd image source code:

for "_i" from 0 to 600 step 0.1 do {
	diag_log str [_i, 1 random [_i, 0.5]];
};

Both show that the return from random is not a perlin noise but just a totally random value.
Beside that, below 0.01 in x coordinate unit results in a uniform value, and in large scale
the random function has some kind of repetitiveness.