There is new version of the net-print/cnijfilter2 than available in portage tree. Version 5.40 adds support for some new multifunction printers.
Link to source tar ?
Here at Canon site https://www.canon-europe.com/support/consumer_products/products/fax__multifunctionals/inkjet/maxify_mb_series/maxify_mb5150.aspx?type=drivers&driverdetailid=tcm:13-1533036&os=Linux%20(64-bit)&language=EN or GIT repo here: https://github.com/endlessm/cnijfilter2
Added