Pale Moon (as an application) will likely never support WebExtensions, even if we would switch to a platform that technically supports its use, because:
- Having XUL/overlay, bootstrapped and SDK/PMKit extensions already provides everything any extension developer could want or need for extension development, and then some. Adding a 4th technology to that line-up that is radically different and more limited in what it can offer by design is a maintenance nightmare and time-sink we simply don't want in our project.
- Pale Moon's front-end doesn't use UI controls or layout that allows html-based widgets (the only way for WebExtensions to interface) to be inserted. As such, it would require a (messy) compatibility layer to enable insertion into our XUL-based UI, and likely will cause many many bugs. Even if a new platform in the future might theoretically allow the use of WebExtensions, Pale Moon's application code will not.
- WebExtensions are too restrictive for anything but the most basic tools and will not, ever, allow true extension of the browser's functionality as a result. This makes the technology used for it undesirable for Pale Moon since it will, by design, fall short from day 1.