Can a Swiftblade with Perpetual Options benefit from extra attacks that don't normally stack with Haste?

Question

A 9th level Swiftblade gains the Perpetual Options class feature:

Perpetual Options (Ex): At 9th level, you can perform even more actions with the haste spell. Instead of making one extra attack at your highest base attack bonus while under the effect of a haste spell that you cast yourself, you now have the choice of making one extra move action or one extra standard action. For example, you could make three consecutive move actions with this ability, two move actions and one standard action, one move action and two standard actions, a full attack action and a move action, a full attack action and a standard action, a full round action and a move action, or a full round action and a standard action.

This benefit replaces one of the ordinary benefits of the Haste spell, the ability to make an additional attack when using the full attack action.

If a 9th level Swiftblade under the effect of Haste uses some other option that grants an extra attack, but that normally doesn't stack with the extra attack from Haste (like the Sakkratar's Triple Strike spell (LEoF), or a weapon of speed), do they get both the extra standard action and the extra attack? Or do these effects still "not stack," even though they're now providing different benefits?

Answer 1

Since the benefits grant additional options when using the haste spell, that makes the benefits subordinate to everything that affects haste, other than the specific exceptions outlined in the benefits. In other words, the options can only take effect when you are under the rules that affect the haste spell.

As the options description does not state that it overrides the non-stacking nature of haste (the options only state that it replaces the attack action with a standard or move action) then whatever would not stack with an unmodified haste still won't stack with the modified version.

Likewise, anything that would manage to stack, still will.

Answer 2

You could probably make a technical, rules-as-written argument for allowing you to benefit from such effects, but ultimately I would apply perpetual options after adjudicating whether any effects are stacking with haste. So I would not allow a swiftblade to use a speed weapon to have their cake and eat it too.