There are a few cabinets and a few modifications I use often that Chief won't do- recess corner sink base, recessed angled plate rack, side access with glass, non matching interiors, integrated side panels, some angled cabinets, unequal depth pie cut...I can make them in 2020 in a snap, export to cad, open in turbocad, export from that to 3ds or SU but STILL I've had no luck importing them as symbols. So...
I eventually have had to build them out or "parts"-loose shelves, seperate backs, cabinet 3/4" or 1/16" deep, stacking multiple cabinets, psolids, loose doors. All in all a PIA but at least I can get there. Once in a while I've had luck creating in a seperat plan-perspective-delete surface add to library- but that doesn't always do what I expect.
Most times now when I can't get the DBX to do what I need I go directly to "custom fabrication"
Alas I have not always been able to reuse these wonders- sometimes block- library and resuse works out, sometimes open old plan copy and paste works out- most times something quirky happens requiring more work. The upside is it helps when talking with the factory.