Not sure if this is a cable or IEM review but good job on the IEM part
I'd give even more praise on the 10mm biocellulose DD. I find it second to none. I heard Yanyin has these in one of their models too. Gotta find them all.

Right, well I fell down the cable rabbit-hole........ there probably will not be another review like this one ever again, by me. But the feature is...........the SERIAL is down for cable rolls if needed. In fact it has an uncanny ability to show cable characteristics, and due to the neutrality, you can often live with them. As far as more bass praise, looks like there is room on this page for you to go ahead and add that enthusiasm for the 10mm DD in your review. Why not! Thank-you for your graphic representation, it really helped me out!

I'm between serial, h40, est50, or vortex, hard to choose, but for you, which one do you find most musically attractive today, without sounding tiring and screaming, and that you can listen to for many hours using a smartphone?

Thanks for the review!

1st off the VORTEX is burning-in, and I just got it a week ago, so I haven’t listened to it too much, so I can’t comment on that one. But I would seriously look into the ISN H50 as it’s great from phone, but it could be on the too bright side for you? The SERIAL is a little hard to drive, making you max out the volume in your phone, yet the SERIAL has no issues like sounding bad from a phone source. In fact most people would be fine (with the volume) from a simple phone with the SERIAL! To me the SERIAL wins out against the H40 due to simply having better technicalities and a more natural sound. Plus it’s more $! .....EST50 is another that is more heavy handed in the bass, which is a matter of taste if that’s what you go for. Where the SERIAL is more neutral and about the midrange aspects. But the total sound of the SERIAL is amazing from a phone! Is better than you could comprehend, maybe? Cheers!

Really your probably asking for the SERIAL? But you won’t go to ear blasting levels.