I found that the 5k-6k peak rendered the Origin too sibilant to work as a vocal set for me.
This is when the well-constructed swappable nozzles were a huge asset, precisely because they don’t do too much. Taking inspiration from the JVC HA-FD01, the predecessor to the FDX1 referenced in @Precogvision 's review, there is a simple tuning mod that is good for IEMs with swappable nozzles. I’ll let anyone who is interested look up the relevant posts on SBAF.
In summary, the mod is done by cutting a small rectangle out of an alcohol pad, then lining the inside of the cylinder with a layer or two of the pad rectangle material. A hefty sewing needle with a large eye helps with the application. For the Origin’s nozzles, 8mm worked the for width. For the length, I ended up with something less than 20mm, but I’m not sure.
The advantage, I find, with leaving a hole in the middle of a physical filter mod is that the hole helps to save more the mid/high treble, while still attenuating that nasty high mid/low treble region. With the FD01 that was about 4k, and with the Origin the problem is about 5k-6k.
The upshot in every variation I tried is that the peak in the sibilance region got under control without EQ, which was my goal. It’s now a great non-fatiguing all-day vocal set.
However, it took a few tries to get the balance right. One of my attempts attenuated the highs too much and another time it killed both the bass and the highs.