Ok, so we’re talking about during development only? From what I had previously read, I thought that you meant for this to be “existent” after a release of the plugin as well.
In that case, of course, many of my concerns are invalidated 
However, I still don’t think that it’s a good idea since it would mean that developing inside the develop
folder would be encouraged. I, however, find this to be unwise for multiple reasons. For instance, this basically means developing things inside a folder controlled by an application. Instead, I think a workflow where one develops the plugin in some project folder (which is one’s own choice) and then install / continously install it with tools like xdpm should be encouraged, since it also adds a layer of protection during development. Also, when build tools such as webpack (with npm packages etc.) get used, this allows testing the compiled version without e.g., the node_modules
folder, already stopping potentially wrong assumptions about what’s included in the build (since the version that gets tested and lives in the develop
folder is already the “real” version).
That being said, I think the question now is whether it should be encouraged or discouraged to develop directly inside the develop
folder. To me (personally), it feels wrong to develop directly inside a “deployment target folder”. Having my full repo (with git, a node_modules folder and everything else) inside an “application-controlled” folder seems odd to me. Therefore, to me this requests feels like encouraging behavior that shouldn’t be encouraged and I (in all honesty) still see no benefits to it. Quite the opposite, in fact: It would add another layer of dependency management to the process (which libraries are handled by npm, which by this shared folder etc.), and dependency management is – in my opinion – already painstaking enough as it is.
Having said that, I will admit that my concerns of course loose their severity with this only being the case during development. Therefore, while I still can’t say I’m in favor of it (for the reasons mentioned above), I will “withdraw” my huge disapproval (with which I would have continued fighting if it had been the way I first though it to be like), since while I wouldn’t find it good for this to be implemented, it also wouldn’t affect me too much, meaning it kind of doesn’t matter to me if this were to get implemented (or at least nothing severe enough that it’s worth fighting against
).