i found nice DAC where charging works perfectly while listening, i had few before what was working fine with android devices, but sailfish when power cable was connected stopped playing music. This cheap DAC from action.com (available in some EU countries) works like charm
for the outside i use Apple dac with tweak for volume level
edit: this adapter is actually unusable for phone calls with JollaPhone 2026 - it looks like phone switch microphone input to this DAC and in case that you have only headphones connected nobody can hear you.