I've ported over my Box2D+ plugin to Construct 3.
Box2D+ is a port of Box2D r2.3.0 emscripten, with added helper functions. For example: you can obtain the collision shape from the image alpha mask, you can set the collision shape at runtime from a C3 array.AsJSON and you can fuse many object together without any joint fighting (assimilate joint - make an object a fixture on another object).
Please visit this thread for a description of the plugin (think Physics behavior on steroids) and visit this thread for a description of the Platform helper plugin (think Platform behavior, but with physics and one-way doors, collision filtering, etc).
The Box2D+ plugin is available here.
The Platform and Flow (helper) plugins are available here.
The threads and the itch.io pages contain demo links, so please have a look and feedback here / in the other threads, depending on what flavour of observation you have.