Very true, but also consider: SAP is a billions of dollar corporation. They can afford to throw like 5 engineers who have specific experience in elastic search

Very true, but also consider: SAP is a billions of dollar corporation. They can afford to throw like 5 engineers who have specific experience in elastic search to fix this in a day. They won't because they have no reason to, but this is software that you sign a contract for, not some random OSS project on github.