I don't have even a fraction of your technical knowledge, but I can offer my experiences: I split the output from my Bifrost Multibit between my Valhalla and Cavalli Liquid Carbon amps. The first time I turned on the Valhalla and left the LC off I found the sound very distorted and it took me quite a while to figure out that the distortion disappeared once I turned the LC on. So it seems that the LC's input impedance when turned off is low enough that it impacts the Bifrost's ability to drive the Valhalla. Once both amps are turned on everything works fine. By the way, the opposite configuration (LC on, Valhalla off) did not introduce any distortion.
I have since purchased a small distribution amp to use between the Bifrost and my amps. This has eliminated the problem altogether.