全く~ない => not at all ~ N3
全然~ない => (not) at all N4
も構わず => without caring; without worrying about ~ N2
も[構「かま」]わず => Without considering A N2
Considering, Concerning
を契機に => as a good opportunity/chance to N2
Expected
を[境「さかい」]に => A is set as a border/limit N1
Degree/ Level/Amount
を[機「き」]に => Use A as an opportunity N1
Time, Situation
を[契機「けいき」] => As a good opportunity A, (do) B N2
Information, Report
[全「まった」]く~ない => Not A (at all; even a little bit) N3
Not only, Not even
をきっかけに/を契機に => with… as a start; as a result of; taking advantage of N2