UR44 functionality compared to Scarlett 8i6

I’m going to keep this as simple and brief as I can…

I’m considering switching to the UR range (the UR44 or UR824, namely) from the Scarlett 8i6 by Focusrite, and I have a few questions.

First, the Scarlett 8i6 has three pieces of functionality that are absolutely critical to me, and that the UR44/824 would have to have:

  1. That it presents itself to Windows as a stereo line-out audio device that can be routed to two or more physical outputs on the device simultaneously.

  2. That it presents itself to Windows as a stereo line-in audio device. The only two inputs that are mapped to this audio device on the Scarlett 8i6 are inputs one and two, which are mic/line/instrument inputs. The UR44 would either also have to map only the first two inputs to this device, or have the option to allow me to choose which inputs to map to it.

  3. That any of the physical inputs can optionally (as in they can also be muted) be routed to any physical output on the device via some form of mixer software, and simultaneously not be heard through the loopback input.

Secondly, the dspMixFX feature with real-time channel strip. Does this real-time channel strip affect what’s routed to the line-in audio device mentioned? E.g., can I have the output from that real-time channel strip be directed to the line-in device in place of the raw input? This is what’s tempting me most.

Apologies for the massive wall of text, but I’d seriously appreciate any input on this front. Thanks in advance!