Hi Rahul,
If you are talking about so many values that often can be changed i recommend you carefully to value mapping mass replication, jdbc lookup can have relevant performance risks.
3. Instead of using ABAP proxy at source end, can we not directly receive the data from MDM using file or MDM adapters and target channel as it is?
You can get the data with any adapter, for the receiver you can only use the proxy.
Regards.