It might be worth a version of the templates that references the following NuGet packages, instead of directly referencing dll's on the local computer. This is more helpful if multiple developers might be working on the tool, and they have different versions of AutoCAD installed.
Speckle is an Open Source collaboration system and they provide this helpful NuGet package to help you include required AutoCAD DLL's
https://www.nuget.org/packages/Speckle.AutoCAD.API/
They also have packages for Civil 3D, and would be easy to swop the AutoCAD package for this one if needed
https://www.nuget.org/packages/Speckle.Civil3D.API
They do also have a Plant3D package but that only includes DLLs for 2026 and 2027 so you couldn't do the triple target with this one
https://www.nuget.org/packages/Speckle.Plant3D.API
It might be worth a version of the templates that references the following NuGet packages, instead of directly referencing dll's on the local computer. This is more helpful if multiple developers might be working on the tool, and they have different versions of AutoCAD installed.
Speckle is an Open Source collaboration system and they provide this helpful NuGet package to help you include required AutoCAD DLL's
https://www.nuget.org/packages/Speckle.AutoCAD.API/
They also have packages for Civil 3D, and would be easy to swop the AutoCAD package for this one if needed
https://www.nuget.org/packages/Speckle.Civil3D.API
They do also have a Plant3D package but that only includes DLLs for 2026 and 2027 so you couldn't do the triple target with this one
https://www.nuget.org/packages/Speckle.Plant3D.API