I've packaged up NSIS 3.0 with the appropriate plugins for both ANSI launchers (Google Chrome) as well as Unicode launchers (Firefox) and apps (PA.c Updater, etc). The reason for the dev test is some additional functionality in the NSISPortable.exe launcher.
NSIS 3 is the first official release that is no longer ANSI only. Previously, PortableApps.com, Mozilla and others used a fork of NSIS called NSIS-Unicode to properly build multi-lingual installers for modern Windows since NSIS proper couldn't. Now, NSIS can compile to both ANSI and Unicode. It does, however, need updated code to know which. Specifically, a build setting "Unicode true" will set it to Unicode mode within the NSI script.
If you pass an NSI script to be compiled directly to NSISPortable.exe, it will check to ensure you have Unicode set to either true or false before passing it on. If you don't, it will warn you and allow you to set it either temporarily or permanently along with setting whether to enable high DPI mode on Windows 10. There can be some problems with this automated method and they are presented to the user as they build a script.
Download NSIS Portable 3.0 Dev Test 1
2MB download / 8MB installed
2016-11-10: First public release