Me too indeed. For now my better options are the E10K (available in the local market at a moderate price but not cheap), a K1 with the odd Fiio warning (half the price of the E10K), and some cool usb soundcard like the Creative HD for a little more than the E10K. Also the 5.1 version which is the cheapest. Hard to tell.
I say just ignore the "warning" and use the K1. You won't harm it or the amp, and the frequency response can't be impaired by driving the higher impedance load of the amp.