Forms Personalization on Match Approval Level

For the following screen under the Payables Manager responsibility...

Suppliers --> Entry

Then onto the "Receiving" screen.

I'm trying to default the Match Approval Level to "3-Way" but still allow it to be changed to "2-Way", "4-Way", and blank.  I personalized the form to change the initial value to "3-Way".  After that, it defaults to "3-Way" and I can change and save it as "2-Way" and "4-Way", but I cannot change it back to blank.  Is this possible?  I am attaching a screen shot of the personalization page.

Tracy Tymko