It's not random. Following thread collects hundred of player experience wich, though incomplete, is better than a single explorer experience. F,G,K, stars have a much higher probability to have an ELW. The contributors in the following thread that discover 3 ELW per evening are not crazy people that jumps 2500 system/hour, it's people that filters galaxy map for only show F,G,K, stars.
https://forums.frontier.co.uk/showthread.php?t=119065
Again, this tell us about F, G, K. But is not a small amount those reported around NS, and also A's and O's.
That's what bothers me most because I might hit 1,000 FGK find nothing but then two NS or A's and find 2!
Last night, for instance, I found a WW that was very, very close to be ELP, so much so it was also a TerraCandidate. What was it orbiting? 2 brown dwarves....
So, on your route of FGK's you skip or pass by M, or brown dwarves or NS, and there is actual chance to find one there as well. Then you dont find any in your FGK stretch and keep scratching your head...what if??
I'm keeping FGK route just because they also bear Hi Metals and TC. But not sure if indeed I have it any better than router only. Mind you 11,000 ly on my current exploration with FGK's and not a single ELP so far. None! How much higher are the chances? Lol. Just a thought.