> That way, you only do the IDL-dance once and the browser then manipulates the tree in C++ with the many operations you fed it.
As a beginning web developer, I remember being surprised that there was no way for me to group DOM manipulations into SQL-like transactions, or even an equivalent to HyperCard's lockScreen.
I'm finding it a little tough to tell whether the author is talking about putting the browser or the web developer in control of grouping DOM updates.
fastdom might be of interest – it batches read and write operations into separate queues and runs them using requestAnimationFrame: