The only way I found to modify bpmn's popup menu is to copy/paste and edit bpmn's files - ReplaceMenuProvider.js
and ReplactOptions.js
:
$ mkdir src/bpmn
$ mkdir src/bpmn/popup-menu
$ mkdir src/bpmn/replace
$ cp node_modules/bpmn-js/lib/features/popup-menu/index.js src/bpmn/popup-menu/
$ cp node_modules/bpmn-js/lib/features/popup-menu/ReplaceMenuProvider.js src/bpmn/popup-menu/