The omnium is betwixt and between, combining as it does timed and bunch events.
From the guardian.co.uk
Betwixt and between, it's not easy being a federal appeals court judge.
From the theatlantic.com
She played the part of spurned lover well, performing the range betwixt betrayal and rage.
From the charlotteobserver.com
Betwixt and between, neither fish nor fowl, and upset at all three of the above groups.
From the economist.com
Obama says Americans feel a sense of urgency, but they appear caught betwixt and between.
From the smh.com.au
Betwixt and between, he intersperses rhythmic lick-ety-split soliloquies.
From the time.com
They can't help that their MCC brethren are betwixt and between rebuilding and reloading.
From the stltoday.com
Named for the Roman goddess, Juno rules a region betwixt and between adulthood and kidhood.
From the denverpost.com
A cupola the size of a small bandstand stood atop the pile, betwixt two fat, brick chimneys.
From the online.wsj.com
More examples
Between: in the interval; "dancing all the dances with little rest between"
Betwixt! is a musical comedy conceived and written by Ian McFarlane. The show premiered in The King's Head Theatre London on 6 May 2008 and finished its first run on 22 June 2008.
Between, specifically between two objects
(bi-TWIKST') Preposition: Between. idiom: betwixt and between. In an intermediate position; neither wholly one thing nor another.