@senya72 yes it was dropped from r13. The idea is definitely sound but the implementation in r13 was sub par. We realized it was doing more harm than good.
One thing I find very often is that "dimensions" want to be shared between arrays and are sometimes multi-attribute. For example:
SAMPLE <name, date, type...> [sample_id]
GENE <hugo_symbol, gene_name,...> [gene_id]
RNA_EXPRESSION <value> [sample_id, gene_id]
DNA_METHYLATION <value> [sample_id, gene_id]
...And perhaps you want the removal of a sample to cascade down to everywhere it's used... So - yes - we are considering these examples and discussing what kind of syntax and features would work best.