Busker Stunts, static rounds per day intentional?

[kadance]

Do the number of rounds a Busker Bard can use his stunts really never increase after first level?

The text for Busker Stuns:

Busker Stunts (Su): A busker knows how to magically enhance the effectiveness of his physical stunts. He can use this ability for a number of rounds per day equal to 4 + his Charisma modifier. Maintaining a stunt is a free action, but it ends immediately if the busker is killed, paralyzed, stunned, knocked unconscious, or otherwise prevented from taking a free action to maintain it each round. This ability is treated as bardic performance for the purposes of feats, abilities, and other effects that affect bardic performance. Like a bardic performance, a busker stunt cannot be maintained at the same time as other performance abilities.

[My Self]

Probably. Archeologist functions like this, too.

[Entryhazard]

At least you can use the feat Extra in order to get more rounds

[graystone]

Yep, most likely the same as an Archeologist. Lingering performance, various ways to increase bard rounds and a Tuned Bowstring will add together to make the fixed number irrelevant though.