Thanks for the suggestions.No. There are many.
Luxury & Precision W1/W2, Moondrop Moonriver 2, Tanchjim Space, Whatever model Hidizs is up to now - no doubt a few hundred more if you scour Aliexpress.
Oh, and the most flexible dongle by a mile- the Qudelix 5k. Balanced 2.5mm (but 4.4mm to 2.5mm adapters are nor hard to find) , 3.5mm, USB C or LDAC bluetooth, 10 band PEQ across all sources etc etc
By 'pretty much the only ones', I was meaning that have been measured