Dear Dimitris;
I am using this tcode in production system. It is used frequently to fix Cash management problems.
Tcode FDFD run these programs;
RFFDDL00 |
RFFUEB00 |
RFFDKU00 |
RFFDZZ00 |
RFFDSD10 |
RFFDMM10 |
RFFDMM20 |
RFFDLF00 |
RFFDINSK |
You may try these reports manually by SE38 t.code, but i do not think you may filter them for some customers.
Tcode FDFD update the CM report with the current stiuations of the customer,vendor,gl,po,pr,so...
It is up to you, to use it or not 
Best regards
Aydın