From Paul at iBasso:
"Hello, The connector is MMCX so it should be fine but we have the mold come down a little further because some didn't like how freely the IT03 swiveled. The molding makes contact and through friction keeps the IT03 from moving so easily. This most likely would interfere with the connection on the Campfire IEM but the molding is easy to trim off that comes down a few millimeters. With it trimmed of it should fit as it is a standard high quality original MMCX connector. I don't have any Campfire IEMs here to try but I have read they are very good. Also the CB13 would be a nice match for expensive IEMs but also would need to be trimmed.
Best regards, Paul"
I have both the CB12 and the Fidue A83 balanced cable coming, so, we'll see what's what. The VE balanced cable was a great deal for $15, but not a permanent solution. Though, honestly, I'm enjoying the Lyra II single-ended so much, I wondering why I'm bothering at all.