Maint and Dev project in one landscape

hi experts

Initially we had a proposal for dual landscape to manage maintenance and development landscape using retrofit. but we have a situation to manage maintenance and implementation project in one landscape.

i.e,  Dev - QA - PROD  - this landscape should manage both development and maintenance projects

My initial thoughts to define the solution

1. create two different projects  - one maintenance project and one implementation project for development team
2. customizing changes are implemented using the TR from implementation project , whereas work bench objects needs to be done using enabling the CSOL. so that developer A and B can work independently using different TR.  - is these possible to have different TR's from two different project for the same workbench object ?
3. Implementation projects TR's will be moved before the test cycle to QA
   
4. during the QA test cycle , if same objects conflict occurs - urgent CR can be created to resolve the conflicts
5. after testing in QA, the implementation project TR will be moved to Prod

Is these feasible and workable solution to implement in landscape ?

Please advice with possible options

Thanks

Sol man