Unfortunately we want to avoid this. Effectively we're trying to create a format that's more akin to `ngettext` - in which you have a singular form and a plural form (for English). These two nodes will be replaced in other languages. For example in Chinese it'll read:

  <span>The length is <var>L</var> <var>plural_form(UNIT_TEXT, L)</var>.</span>

(in that there will be NO data-if/data-else case as in Chinese there is only one plural form) Additionally in a language like Polish where there are 4 plural forms there will be a data-if/data-if+data-else/data-if+data-else/data-else series of nodes.