Can I compile an engine plugin as part of a game build?

I have a custom actor class that I implemented in C++ for a game I’m working on, providing improved control over a SplineComponent’s points (specifying exact position, rotation, etc.). It’s working well enough that I thought I should make it available to all my projects, as well as put it online for the sake of any other UE devs who might find it useful. Those requirements led me to try developing an engine plugin. Implementing my idea that way may or may not turn out to be the right design decision, but I still want to try this out if only to get familiar with plugin development.

Unfortunately, I can’t get the plugin to compile when it’s in my Engine/Plugins directory unless I recompile the entire engine, which I think goes a bit against the principle of plugin development. Nothing in my plugin depends on any private engine code, only standard public headers, and everything compiles as expected when it’s placed in my project-specific Plugins directory. That, combined with my admittedly limited experience with shared libraries in C++, has me convinced that it should be possible to build the plugin without building the host application (i.e. the Unreal Engine), I just can’t get the build system to do it.

I’ve tried a tremendous number of things at this point, and read more Answerhub questions and forum threads than I can count, so to avoid overwhelming people with likely unnecessary details I figured I should stick to confirming the basic idea first: should it be possible to have an engine plugin recompile if stale when I compile a game project that uses it, or do I need to develop it as a game plugin and then move it to the engine for use and distribution?