Not being cancelable makes validating dialog content impossible - eg a login dialog or anything that takes user input. Of course, it's easy enough to get around - but I think this should be a requirement of a dialog.

The first rule of standard is no configuration. Whatever the outcome of this thread, adding options is the wrong solution.

A zero-config development setup is provided, but nwb also supports configuration and plugin modules which add extra functionality (e.g. Sass support), should you need them

Create and build modern JavaScript applications with zero initial configuration

Setting up Nginx properly requires quite a bit of work. Using websockets or using Rails streaming? Make sure you disable response buffering for the relevant URIs, otherwise they won’t work correctly. Phusion Passenger 5’s builtin reverse proxy does the right thing by default, without any configuration. In other words: it’s all about making things simple.