My quick perusal through the vicor docs does not indicate a need for any capacitance where you have placed circled capacitors. Although I see caps located in those areas in one application note, there is no mention of them in the note. The internal input and output capacitance of the modules is already quite large (5uF), so that is the minimum capacitance achievable.
Vicor has an applications assistance contact number that is a good place to ask, since this is a issue specific to a complex vendor-made module.