A PPK loaded with Magsafes under the shirt over the vest in a "Superman" carry... worked very well for me.
But an Operator is probably wearing the Cover Six by Safariland or another Ninja Turtle uniform... so the Superman carry would not work. The 3rd weapon will need to be fast to draw as all weapons for this MIB.
Ankle holster is out in my opinion.
I would think maybe a cross draw carried under the web belt... PPK would fit there snuggly. Or mayby an SOB rig? Ankle is only last ditch for me.
Kenetic Defense Institute