Hi PK,
In ChaRM- Retrofit functionality will help in order to keep the two development system in sync.
How you design the transport route between the support landscape and Project landscape.
Both are in separate transport route?
Normally the support landscape and Project landscape having same Production landscape( but u have mentioned PRD1 and PRD2)
https://websmp204.sap-ag.de/~sapidb/011000358700000413492011E
Maintained the logical for retrofit as shown below
Please check the document .
After Transport released in Dev system( maintannace landscape, MNT), TOC is created with retrofit data in MNT system.
Goto project landscape and create the TR in task list.
then start the retrofit , it will show source TR , then select the Retrofit TR's( which is cretaed in the project or impl landscape and select Auto-import.
Also if required more details, provide the transport route of both landscape for more input.
Rg,
Karthik