Hi Don,
I think you are asking whether your PB C# project must be maintained in the PB IDE or whether you can use other C# IDE like Visual Studio?
If I'm understanding your question correctly then the answer is yes! This was outlined at a high level in the "portability" section of the PB 2018 Preview: https://www.appeon.com/pb2018.html#portability
But keep in mind that the metadata information for C# DataStore is quite complex and so it may not be productive to edit that without using the DataWindow designer. This is why we also provide the C# ModelStore as replacement for C# DataStore so customers can easily maintain the product in any C# IDE with same productivity as using the PB IDE.
Please note that the DataWindow migration feature shown in this video works for both the C# DataStore and the C# ModelStore: https://youtu.be/cglOa-PIHBg
If you have different question please create a different thread. If this answers your question please accept this answer so this question is marked as "resolved".
Thanks,
Armeen
Don