So without a DAC dongle, there wouldn't be much difference between the Olina and the S12?
You're right in that my next phone will not likely have a 3.5mm jack. I generally prefer budget phones like the Xiaomi's, but it seems that even the budget phones are moving away from the 3.5mm jack so I might have to get a dongle anyway. But when the time comes, I definitely won't be getting something large. So my next question is, would even a small dongle, like the ddHiFi TC35B, be enough to realise more of the potential of the S12. Or, would I need something bulkier?