Parcel
Unfortunately, Parcel 1 does not have the necessary integration points or native module support to be able to have its own plugin. However, if you wish to do the integration yourself, Electron Fiddle can be used as a model for how to use Electron Forge in conjunction with Parcel 1.
We hope to work with the Parcel developers in the future as they work on Electron support in Parcel 2.