Hi Sachin,
There is no such limitation, otherwise why would microsoft allow to copy Production to Sandbox. The URL (technet.microsoft.com/.../dn659832.aspx ) clearly states purposes of copying:
User acceptance testing
Upgrade testing
Preview in production (TAP/EA)
Training
You do not get it as managed copy for sure, you get the copy exactly similar to what you have in production. for e.g. if you have following solution in production:
Sales (Unmanaged)
Service (Unmanaged)
RibbonWorkBench (Managed)
You copy production to sandbox and you will get following in sandbox:
Sales (Unmanaged)
Service (Unmanaged)
RibbonWorkBench (Managed)
Now when you have to have development/configuration in sandbox; go to settings>>solutions>>click on new and add all entities or components you would like to change and later move this solution to production, only if you want these changes to be made available on production
here's a good read on solution management in CRM:
www.inogic.com/.../solution-management-with-dynamics-crm-2016