'cos it ain't in the CIVA Aresti catalogue as a power figure, hence isn't in International power aerobatic competitions.
It is in domestic Glider aerobatic competitions as a widening of the repertoire at Sports and Intermediate, as are varieties of quarter clovers, where machines and pilots can't do some of the figures at Unlimited Glider.
However, both these figures DO have a place in Beginners/Standard power domestic comps., for similar reasons. They provide useful co-ordination exercises without over-stressing pilot or machine and can be quite hard to do really well - sufficiently not to lose too many marks, anyway!
Cheers,
The Odd One