...and if there is no shortcut how could this be done with VBA? Surely a property is exposed in the Visio object model that can use to toggle this setting.

Hi,

As far as I know, there is no shortcut for "Select shapes partially within area" option. And then, I also checked the Visio object model list, there also seem has no related property/methods/event.

Reference:

https://msdn.microsoft.com/en-us/library/office/ff766485.aspx?f=255&MSPPError=-2147217396

Regards,

George Zhao
TechNet Community Support

George,

Thanks for taking the time to reply. Your research into this issue determined the same things as mine, hence my post. Unfortunately MSs all too common response of it just doesn't work that way is not going to cut the proverbial mustard this time and is unacceptable. 

What recommendation do you have for escalating this issue with MS?

Hi Allen,

Thanks for you feedback. I'll collect the information and submit it with internal channel.

Regards,

George Zhao
TechNet Community Support

It's a registry setting:

HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Visio\Application\AreaSelection

1 = Select shapes partially within area - ticked

0 = unticked

Of course, the "14.0" will vary with different Visio versions.