The primary issue is that Black Mage wants as little time in UI as possible. In every situation we have now, from low level to high, this remains true. Even at early game, buffing the ice spells only prolongs the inevitable shift.

It would require a fairly significant retooling of the spells we have access to to make Ice Stance worth expanding its duration on, but even those would likely be relegated to "Make fire phase better". If we do end up in a scenario where Ice and Fire have a more equitable balance (50/50, 40/60), I wouldn't mind Ice being an active phase of MP restoration like it works in PvP, with the goal being to minimize the spells needed to hit max MP while also maximizing the damage you put out.