Okay, I've decided to start on my commercial, and after looking at
61.129 I have painfully accepted the fact that the 300nm cross country
really needs to be vfr, solo

Are you sure it has to be VFR? Assuming you have 61.129(a)(2)(iii), the PIC
100nm VFR XC covered, 61.129(a)(4)(i), the 300nm solo XC doesn't seem to say
anything about VFR.

I agree though, that the definition of solo for the purposes of this
requirement should be broadened to include flights with non-pilot
passengers.

- Ray