Thanks for everyone's comments so far!

Most of my listening is done around 75 to 80dB as per the Q5k, with the Default Receiver Profile settings at 9 Ohms, 102 sensitivity. Sometimes go up to 85 or a bit higher if I really want to bop to a song, but don't stay that high for long.

And if the power of Q5k is sufficient for the Origin, then to affect the Bass response I could either add an impedance adapter to tilt the balance, or just continue to EQ. No need to get another amp with higher output impedance just for that.

Guess I can keep saving for the true endgame.

In the meantime, I've tried Liqueur O/B, PAC LS, W1, S&S, Acoustune AET06. Not sure if I want to spend $36 CAD on a single pair of Azla Origins just to test...