Under these conditions you can not depart VFR.
Do you have any references for this? My understanding is that, as long as the gaps in the clouds are sufficient for you to get 500' from buildings, structures, vehicles, etc etc, there is no legal reason not to depart VFR (whether it's wise or not is a different matter). But I'm not certain of this, and if you can find anything to the contrary I'd be interested to read it.
FFF
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