hi all im new can somebody shed some light on this issue

little story

i have an audi a3 Dsg S line 140 2007 with engine code BKD im losing coolant every week there are no visible leaks i have the pressure testing done there was no leak in any hose pressure was holding as it should also ive replaced the coolant cap on the resivour bottle also. im aware of the porous cylinder head on these engines my part number for the cylinder head is '03G 103 308 C' i know the A and B had problems the cylinder head cracking. can somebody else with similar experience and a success story shed some light? im clueless right about now?

thank you