Solution : https://service.sap.com/sap/support/notes/1608649 (SAP Service marketplace login required)
Key words : 
jdk-internal implementation left, transformer object meant holding, symptom sap jvm 6, sap jvm build 6, creating xsl transformers, important bug fixes, reusing transformer objects, sap jvm patch, 1 patch collection 25 relates, multiple payload documents
Related Notes : 
       
| 1434916 | How to find out the SAP JVM build version | 
| 1367498 | SAP JVM installation prerequisites | 
| 1249462 | How to import an SAP JVM patch into an SAP BC | 
| 1133020 | How to import a SAP JVM patch into an AS Java |