I did own several diesels in pickups and cars, some of them exceeding 300,000 miles and never add anything.
ULSD is not doing much for cleaning, but CA was always adding some cleaners to fuel and lately all states add bio-diesel.
Bio-diesel is having good cleaning characteristics and few years ago I could find it in my travels for less than diesel, so I was filling it up few times a year. Common advise is to carry extra fuel filter for such occasion as bio can dislog gunk in fuel tank, but I never had such experience.
Lately bio seems to vanish from California pumps, but then if you read, regural diesel can have up to 10% of bio in it. Good enough for me.
Than some states add up to 20% bio and that create problem in new diesels, that are design up to 5%.
Final conclusion, check how much bio you are pumping. The detailed info should be available at gas station.
When you have more than 5% of bio in fuel anyway, why worry about anything else?