That is an interesting question. When I was a teen I did not pay much attention to strings and just played some very bright strings. That and a pick was all you needed for punk music. All I knew is that I absolutely hated some strings (I was talked into getting LaBella Hard Rockin' Steel strings in the mid 90s by someone at a big music store and I don't think I have ever despised other strings that much aside from maybe Ernie Ball strings).
Anyway, when I started with short scale basses, I went with flats because it just made more sense. I do use some of the relatively brighter flats (TIs and Roto77s). I say relatively because, hey, they are flats.
You kind of bring up a very interesting point because EQing before effects is sometimes very important. With my Bass that has TVJones pickups, I get very very different reactions in my dirt pedals especially. And, it's nit just due to the fact that the pickups are hotter. It might be better to always be able to start with a milder tone and add EQ before effects if you want. Like starting with a cleaner slate.
It's all hypothetical for me though because, when I played with bright strings, I played with really bad effects (guitar pedals that sucked the life out of the bass).
Juan Alderete posted about his evolution on strings. How he went from rounds to flats and then to tapes.