Would not a cable splitter suit your minimalist needs?
Yes! That was my second option but might become first :-)
Not ideal (how much do I lose in terms of sound quality?) but defnitely feasible.
But wait.
overover said the E463 has a build in audio interface, to connect directly with a computer and a software DAW.
I don't have a computer but I have an iPad and iPAD can have DAW apps installed, i.e. Multitrack DAW. This is actually an audio recorder (not midi) but it's not a hardware recorder such as my Tascam, which requires audio out/in as you said.
So that can I connect my E463 directly to my iPad and record with the DAW app, by connecting the USB to HOST port to the iPad with a simple lighting cable (but without a digital audio interface converter in between such as the Behringer UCA222 - actually I have one, but don't like it much.... signal loses some quality imho)
Thanks!!