Crazy cross-MIPS-boards stunts possible?

I'm curious about a few wild "for fun" ideas:

- I remember binary emulation working on several exotic platforms and
   their commercial incarnations. Would it be impossible to run IRIX
   binaries in NetBSD with something similar?

- What about binaries between MIPS and SGIMIPS ports? Is that impossible?

- In qemu, do any of these work for running netbsd? I looked here first:
   https://www.netbsd.org/ports/emulators.html answer is "no" ?

What's on my system in the way of Qemu + MIPS:
qemu-system-mips      qemu-system-mips64el
qemu-system-mips64    qemu-system-mipsel

- Is there any way to cross compile for IRIX in NetBSD ? (Sorry, maybe
   should ask in SGIMIPS, but thought some MIPS guy might know).

Is the little EdgeRouter the closest we're gonna get at the moment to a 
cheap single-board MIPS "RPI"-style board or is there something better 
right now supported in NetBSD?

Thanks,
   Swift