Dimensions don't apply for item type 'Music'?

Apparently, the dimension field does not have any effect for Music-items. Ok, for items that are marked as having a jewel case, ignoring dimension is a good thing. But there are deluxe editions, box cases, etc. where you could switch the appearance to the "paper"-type and additionally use the dimension to make it appear like the original.

However, also for paper-appearance unfortunately the dimensions don't seem to apply.