\omit multiple/list

[damianlegassick]

Hi all how would I reduce e.g. \once \omit TupletBracket \once \omit 
TupletNumber \once \omit Stem to a structure conceptually like: \once \omit 
(TupletBracket, TupletNumber, Stem) i.e. put the grobs in a list thanks Damian