We tried exactly that using a hidden int slider that is incremented via FxPlug4's param action and get/set APIs. In our particular case this mechanism is triggered from the callback of another custom parameter. However, it seems that it doesn't work reliably at all. Sometimes FCPX will initiate a render pass, sometimes it won't and we still haven't figured out why. Did anyone run into a similar issue? This is related to the following thread: https://developer.apple.com/forums/thread/708894

Can you share the details of how you made sure the PluginManager.framework is embedded properly into your XPC? Our pluginkit targets use: xattr -cr "$CODESIGNING_FOLDER_PATH" codesign --force --timestamp --options runtime --sign "${CODE_SIGN_IDENTITY}" "${BUILT_PRODUCTS_DIR}/${FRAMEWORKS_FOLDER_PATH}/PluginManager.framework" We're still seeing "The binary uses an SDK older than the 10.9 SDK." or "The signature algorithm used is too weak." messages when trying to notarize the XPC.