rushlight said:
Applying a standard metamagic feat only increases the slot level (and all increases to a slot level are indeed cumulative). The Heighten spell feat is different, as it affects the effective level of the spell - which, of course cannot be higher that the slot level, but can be lower than the slot level in a variety of circumstances.
And why exactly should that be the case?
Heighten Spell is a metamagic feat like any other. Yes, it works slightly different, but that doesn't really matter.
Applying Heighten Spell also changes the slot level, just like any other metamagic feat. The effect of Heighten Spell is, that it changes the effective level by the same amount, the slot level is changed by Heighten Spell.
Metamagic feats are always applied by themselves not in some weird combination. If multiple metamagic feats are applied, they are both applied seperately and then added together.
If you do it your way... adding Maximize to burning hands to get to 4th level, then add Heighten to raise the effective level to 4th without changing the spell level, neglects the fact, that metamagic feats (including their costs) are cumulative. "Changes to its (the spell's) level are cumulative." Heighten, applied to burning hands, to raise the effective level to 4th also raises the spell level to 4th. "A heightened spell has a higher spell level than normal... The heightened spell is as difficult to prepare and cast as a spell of its effective level." Those +3 spell levels are omitted in your way of thinking. This is not possible, since the rule I quoted absolutely clearly states, that the changes to the spell's level are cumulative and thus are added together, resulting in 7th level with Maximize applied as well (before or after Heighten makes no difference).
Bye
Thanee