Dynamics 365 Plugin Dev Tools
Solution 1:
Personally I use none, but rely on an Azure DevOps pipeline to deploy everything.
For client side development I heavily use Fiddler 4 with auto responder rules with a local webpack devserver. I am not sure how to improve this process much more.
For serverside Plugins I prefer using ILMerge Build Tasks (check nuget) and separate the IPlugin interface implementation from my code so I can easily write unit tests for that. I do not use testing libraries like EasyRepro or XrmFakeEasy. I don't think they add a big benefit and more or less negate one of the best effects of unit testing. Creating good testable code.
For plugin deployment I currently use spkl by Scott Durrow and it is working fine so far.
For generating early bound classes I use a custom .bat file that actually just calls the CrmSvcUtil.exe with a couple of extra .dll files that helps creating enums instead of optionsets.
I am not a huge fan of toolkits or templates that dictate how you have to write your stuff, because most of them embrace bad programming patterns. For example the XrmToolkit forces you to use a certain folder structure for your clientside scripts to not mess up your crm system and so on.
Solution 2:
XrmToolkit is a commercial Dynamics 365/CDS development add-on that is actively maintained and supports Visual Studio 2019.
I have been relying on it for years to assist with generating proxy classes, registering and publishing plugins, publishing web resources on save, etc.
I have no affiliation with XrmToolkit.