I can vouch for Truthear Red. Truthear Gate is not in your list but is also a good generalist you can plug in to any 3.5mm jacks without worries. Truthear Red is better paired with a CX dongle for maintaining the intended frequency response. CX dongles are available
on Aliexpress, any brand will do, the important thing is that the internals match the quality of DAC-amps costing 5-10 times more.
Just checked out the Truthear Gate - seems to be new/recently released product, low cost, entry level. And another decent "starter" IEM. Bonus- it comes with a leatherette pouch.
Challenge is now I have the CCA CRA, not sure of the benefit of getting another "starter" IEM. Sure these things are now thankfully inexpensive. Last thing I want is a pile of inexpensive - good quality IEM's lying around, doing nothing, just because I want to feed my gear lust. Must resist the temptation. Hate to waste money.
From what I can deduce so far, the CCA CRA sounds as good as the source. Feed it some modern saturated audio, it shows you exactly what is there. Feed it a high end jazz, or well mixed song - from one of the top artists, e.g Natalie Cole, Beyonce, and you hear a better result.
I had thought of getting one each of the popular DAC chips - e.g CX-31993, or the ALC5686, and the CS43131 and maybe the ESS90382M, in either dongle or desktop form factor, but I'm not a lab, or a collector, already have too many audio interfaces which I do not use daily, so as I do not need or value MQA, bought a Tempotec Sonata BHD which was on sale on AliExpress - awaiting delivery. This has dual CS43131, and superb measured specs - more than good enough for desktop use - several times more power than the Apple dongle. I'm estimating I'd have to attenuate by about 60dB in the digital domain, to match these with the CCA CRA, for normal long term listening. Which introduces its own issues. Ideally I would like to have the audio coming out of the dongle at its ideal operating range - not hitting the limits like 0dBFS, but somewhere between -5dBFS and -20dBFS. One more dongle DAC to join the Apple dongle is enough. No more dongle DAC purchases, after the Tempotec Sonata BHD arrives.
With low impedance, high sensitivity headphones, causing one to resort to huge attenuation like -50dB or -60dB, wondering if I'll not be ruining the quality of the audio. From my review of the linearity tests on most DACs on ASR, I think most DACs should still be ok, and produce clean flat frequency at up to -60dB. Nevertheless, thinking that I'd prefer to attenuate in the analog domain, to avoid any potential frequency accuracy anomalies in the DAC at very quiet output levels, from needing to attenuate far too much in the digital domain, when I have these low impedance high sensitivity IEMS.
Solution would be - to attenuate no more than 15dB in the digital domain, i.e max peaks coming out of the dongle would be about -15dBFS, feed the output of the dongle DAC, to my Sabaj A20h headphone amplifier, which is then responsible for any further attenuation/loudness management, in the analog domain. Of course I may be overthinking this, as digital attenuation down to -60 or -70dBFS may still be perfectly OK and do the audio output from a dongle DAC, no audible harm. With many dongle DAC's reaching SINADs of -109dB or better, that still leaves approx 39dB dynamic range, (109 minus 90). which is more than enough for most modern pop music.