Ok that is a little more acceptable so they are currently on 2.8 version of web appbuilder 2.9 will probably be released by December, could you use the 2.9 version of the smart editor and share like the following
http://enterprise.arcgis.com/en/portal/latest/use/add-custom-widgets.htm
I have never done this, but may be a workaround for now.
Mark Yerington │GIS Manager│ GISP
Muscatine Area Geographic Information Consortium
c/o Muscatine Power & Water | 3205 Cedar Street | Muscatine, IA 52761
Office: 563.262.3316│Cell: 563.260.4525 Email: myerington@mpw.org│Web: magic-gis.com<https://magic-gis.com/>