The phrase "almost ancillary" is correct and usable in written English.
It can be used to describe something that is nearly supplementary or secondary in importance or relevance.
Example: "The new policy changes are almost ancillary to the main objectives of the project."
Alternatives: "nearly supplementary" or "virtually secondary".
Think about ancillary products.
Her $500,000 first prize, which pushed her career earnings past $17 million, almost seemed ancillary given the stakes that Ko and Park were playing for this week.
Rick Warren's "The Purpose-Driven Life", published by Zondervan (now a division of HarperCollins) in 2002 has sold almost 20m books and ancillary products.
(No messy brush strokes to mar the show's surface, although the retrospective of Leon Golub's paintings of mercenaries and torturers at the Brooklyn Museum of Art might almost be considered an ancillary event).
As of 2011, the Tiruchirappalli division employed about 10,000 people, and is supported by a number of ancillary industries producing almost 250000 tonnes of fabricated materials.
The Baixa remains rigorously protected from change, but the four-story buildings that long lined Avenida da Liberdade and its ancillary streets have been almost totally replaced by taller edifices in a bland modern style.
Both storage technologies are capable of providing an almost identical range of balancing and ancillary services.
Investigated plant concepts with natural gas and syngas-based chemical looping method produce 500 MW hydrogen (based on lower heating value) covering ancillary power consumption with an almost total decarbonisation rate of the fossil fuels used.
Not surprisingly, the number of laboratories and ancillary spaces BTRL required increased almost twentyfold, and 25 times more personnel than originally envisioned staffed these additional areas.
To begin with, case-mix methods almost always involve a DRG classification system and ancillary information; for example, partitioning of same-day cases.
