The javascript build time in our project increased by a factor of 4 when we moved from to (the main compile task increased to 16 seconds from just 4s - we use 'sencha compile').

My guess is that the compiler's auto-dependency detection became a lot smarter... but also a lot slower.

If this is indeed the reason, I'd like to point out that we would rather prefer the faster compile time to a smarter dependency detection. For the (rare) scenarios where a dependency is not obvious we are all fine with adding the necessary compiler hints (//@require...).

Is it possible to disable some of the newly introduced parser features?

I understand that this must hurt because you invested much effort into making the compiler smarter, and I guess it was worth it to help smooth the out-of-the-box experience for smaller projects and programmers new to ExtJs/Touch (or Sencha Cmd) - for larger projects, however, I'd consider it a good investment to fine-tune dependencies manually in favor of faster build times.

One reason why I immediately fell in love with the new Sencha Cmd was the much faster build time compared to the older Sencha SDK Tools.