Is it actually possible too start co-op with $ONMISSION=0 and or rampages. Holding phone calls doesn't seem to work.

Can you maybe get ONMISSION=0 with a side mission and as its about too fail you start co-op and it fails during the fade-in. Sorry if i'm not just trying this myself but im also wondering that the properties seem different for co-op like you can't go in buildings and such.

So is it any different than the normal ONMISSION=0 like for most missions or is it more complicated then that with more obscure properties