Why doesn't a frothing drink overflow the glass? When you pour an aerated (fizzy) drink such as lemonade or beer into a glass, the froth rises above the liquid level, but usually stops rising when it reaches the rim of the glass, even though you keep pouring and the liquid level continues to rise.
Obviously if you overdo it, the froth does overflow, but generally the froth height seems to be limited by the rim of the glass.

Secondly, when pouring champagne into a glass, it is usually so lively that it easily overflows the glass. The hack is to first pour a dash into each glass, and then go round them again. Now it doesn't overflow so readily.
What is the science behind these behaviours?
 A: Foam is weird. A strange colloidal suspension of liquid and gas that can act as a solid but still has some properties of a liquid ( surface  tension, capillary action). While foams can keep their shape, it's not guaranteed and dependent on surface tension, self adhesion, and gas pressure in individual bubbles. Beer foam keeps its shape much better than champagne foam for these reasons.
As a carbonated liquid is poured, foam is created and grows following the shape of the glass. During this process the foam adheres to the glass (partly due to capillary forces) as the foam rises. When the foam reaches the rim the change in capillary/adhesion forces stretch the bubbles until they break at the rim. The popping of these bubbles wet the rim of the glass and eventually, the capillary forces will wick the foam over the rim if the pouring is too aggressive.
I don't have an answer to your champagne pouring strategy except to suggest that the initial pour allows a "softer" follow up pour by replacing a liquid-solid collision with a liquid-liquid collision.
A: Champagne appears to more carbonated than most other drinks. That would easily why champagne is more "lively". Never heard of any "corking"-type behaviour on other drinks so I would think champagne is more carbonated than most.

Beer = 2 to 4 volumes, or 2 to 6 g/L.


Seltzer = Around 4 volumes, or 6 g/L.


Champagne = Around 6 volumes, or 8 g/L.

https://www.seriouseats.com/cocktail-science-what-is-carbonation-how-to-carbonate-soda-better-carbon-dioxide-facts
