The phrase "in an incidental manner" can be replaced with various synonyms that convey a similar meaning. For instance, "accidentally," "coincidentally," "in passing," "unintentionally," "peripherally," "tangentially," and "en passant" all encapsulate the concept of something occurring without it being the main focus or intention. Additionally, "secondary," "auxiliary," "subsidiary," "supplementary," and "ancillary" could be used as adjectives to describe a supporting or complementary role, rather than the primary emphasis. These synonyms offer flexibility in language and expression, allowing for more precise communication and a more nuanced understanding of the nuances of incidental occurrences.