I've long thought that BLM should start doing the F1 vs. F4 dance at a much lower level.
Specifically I'd have BLM learn Enochian and a spell called "Dark Fire" at like level 20 or 30. Dark Fire would hit harder than Fire but not refresh AF. Then at level 60, Dark Fire upgrades to Void Fire, which is just a renamed Fire 4.
This would also mean that High Fire 2 could just be named Fire 4, as well as HB2->B4. Generally, the "dark/abyss/void" etc spells could only be used under Enochian and the appropriate elemental aspect, while spells just named Fire or Blizzard could be cast without preconditions. The end result would be functionally identical to the BLM we have now, but players would learn the basic dynamic of the job much earlier.