I went back to single flange tips for the last couple weeks to see if I've been wrong, especially since triples do make the sound warmer (which I don't really like), and if I need to eq the lower frequencies, I might as well just use single flange and eq the high frequencies instead. Turns out, triple flange is still better, because in addition to fix ear canal resonances, it also removes these dips around 9 kHz (very noticable on Truthear Gate), which are hard to eq back in.

I used sine sweeps and the flac version of this track to check: https://youtu.be/J9yy81yLuOE. This is a bright mix, and on your shouty single flange pos, the hi-hat and synths will sound more prominent than the voice. On my triple flange pos, the voice is the center of attention, as it should be. (The voice actress of Setsuna has such a cute voice.)

I use a bit of eq to address the added warmth, by using a lowshelf at 1 kHz, -2 dB, but this is probably depending on taste, I do like a bright-ish neutral sound. Treble is just perfect, no need to eq.