Can anyone explain what the second paragraph of ancestral surge means?

[Manykittens]

The text is:

If you have available Spell Points, you can spend 1 Spell Point and Concentrate on a Spell to extend its duration by 1 round.

Does this mean that when you cast ancestral surge you can extend the duration of an active spell beyond what is written in the spell’s text by: 1. Spending one additional spell point? 2. Spending a spell point and an action? If either of these, I have follow-up questions.

…Or does it mean that you can spend a spell point to have the action used for ancestral surge count as the “Concentrate on a Spell” action for one of your already-active concentration-duration spells? (similar to the effect of effortless concentration)

…Or does the “its” refer to ancestral surge, allowing you to spend an additional action (or maybe just a spell point) to have ancestral surge end at the end of your next turn (like a concentration spell) instead of the beginning?

…Or does it mean something else that I am completely missing?

[Fuzzy-Wuzzy]

Manykittens wrote:

The text is:

If you have available Spell Points, you can spend 1 Spell Point and Concentrate on a Spell to extend its duration by 1 round.

Does this mean that when you cast ancestral surge you can extend the duration of an active spell beyond what is written in the spell’s text by: 1. Spending one additional spell point? 2. Spending a spell point and an action? If either of these, I have follow-up questions.

The second one (Concentrate on a Spell is an action).

Manykittens wrote:

…Or does the “its” refer to ancestral surge, allowing you to spend an additional action (or maybe just a spell point) to have ancestral surge end at the end of your next turn (like a concentration spell) instead of the beginning?

This one. (Should probably say "the" duration not "its" duration.) Also note that you can do this every turn until you run out of Spell Points or get bored.