I have to agree with your preference with a bit of a twist. I like neutral, but I also like musical. I have found that IEF curve with the lower end boosted a touch (about halfway between the Timeless, and the target on your graph, to be pretty close.@SilverEars I don't find it at all like KZ response. KZ is very peaky in the upper mids and treble in a way this isn't.
The S12 does have more upper mids and treble and closer to Harman but it's smooth and I don't find it fatiguing. I find KZ very fatiguing. I think a lot of this comes down to the wonkiness in the KZ treble response, it's not just the amount, it's the way it oscillates up and down.
Maybe also something about planars, I found the Hifiman Ananda quite bright when I first got it, but not at all fatiguing.
Timeless is below below the Harman IE target for pinna gain but most IEMs are. I usually find IEMs that actually match Harman in that area too much. It's closer to Crinacle's IEF target in this area, which I usually prefer to Harman.
Most popular IEMs are closer to IEF than Harman. Stuff like the Moondrop Starfield, Aria, Blessing 2 / Dusk, Variations, S8, ThieAudio Oracle, Clairvoyance, Monarch, Monarch Mk2, Dunu SA6, Shuoer EJ07M, MEST Mk2, these are all below Harman in that region and closer to IEF.
It's hard for me to think of a popular IEM that actually hits Harman IE; the Galaxy Buds+ did but I found them shouty.
The S12 though I don't, I actually find that really good. It is brighter than the Timeless, but it's not fatiguing, it's not too much. They just sound great.
@sebek I have the Ananda and the Timeless, the Timeless I think is maybe a little more V shaped but if you like the Ananda sound signature you could well enjoy it. Key difference, it's an IEM and won't have the remarkable spaciousness of the Ananda soundstage, but that's inherent to the form factor. Using wide bore tips attenuates the bass a bit and I think improves the soundstage. I liked the results with JVC Spiral Dots and currently using Whizzer EasyTips SS20 "Sound Field" which for me work really well with the shallow fit and seem to help with broadening the soundstage.
I am not a fan of Harmon at all, though it is not utterly horrible. The two things that I don't like in tuning (that is frequently overdone) is super boosted bass (especially mid-bass), and way overcooked pina gain. For me if it is overdone, it not only makes it shouty/shrill but also makes the overall sound signature sound tonally off.