Hi Dell
I can always count on you asking DE greatest of questions 
The "party line" is; it is not the app you will be working in that is supported or not, it is the framework. Thus that BI 4.0 SDK for .NET will work in Delphi, or VS 2013 as long as these support the framework BI 4.0 works with (e.g.; 3.5 and 4.0). Now. Since the BI 4.x SDK is only to be used in managed applications, there is no craxddrt.dll version 14.x installed and thus no CR designer in the .NET IDE. I have never seen this documented in an official type of doc. However the BI 4.0 PAM says:
Contrast this with 'SAP Crystal Reports, Developer Version for Visual Studio .NET". As the install of this product does incorporate the craxddrt.dll into VS to give us the CR designer in the .NET IDE, there is a dependency on the correct version of VS (e.g.; SP 10 for VS 2013, SP 4(?) for VS 2012).
I suppose all of this boils down to; yes, migrating BI 4.0 SP6 code from VS 2010 to VS 2013 should work.
- Ludek