I've comparing between Allo setup and Volumio Primo. I am glad I blind folded myself and gave RaspDac LTE a try. I-Sabor ES9038Q2M is no shame (Thanks to Audio Science Review). The chip is not all there is to it. Thanks to AudioPhonics, the separated power supply fixed Raspberry Pi 3B+'s shortcomings. The noise level is impressively low.
Sound quality is great although sound stage is not as full as my Schiit modi 3 + Vali 2 combination. However, the sound quality is high in crisp, accurate, and crystal clarity.
The Volumio setup is not been very kind. At boot up Volumio would recognize I-Saber ES9038Q2M but you won't get any sound. You need to first turns off D2I setting and reboot. After reboot the driver again won't recognize correctly. You need to ignore "Output Device" first, but manually choose DAC to ES9028Q2M, then reboot again. I am sure this is not faults of AudioPhonics. It's more of the Volumio software bugs.