F21 LIve USB failing on Chromebook

[john.tiger]

usb boots fine on macbook air (WITH holding option key)

on Acer 720 Chromebook the install screen shows - then fails  (F20 usb 
boots fine on this machine)
I've tried different mem settings mem=1024M  mem=1096M  mem=2048M 
mem=2080M  none work

googling returns mostly  garbage

Since the whole point of Live CD is for non-Fedora savvy people to try 
Fedora (and Linux):
a) Install either needs to get fixed - or  right memory setting needs to 
be figured out
b) instructions / FAQ need to be more clear, easier to understand - they 
are not - a better FAQ is needed (we're happy to help here if we know 
where to submit a new draft

btw since most new people using newer laptops will have to create an 
install usb - we have found the dd methods do not seem to create 
bootable drives and the instructions to make it bootable are obtuse at 
best (is it toggle N or toggle X - too confusing)  - we did find 
gnome-disk-util works very good both with Nautilus and xfce Thunar - no 
idea how it works from Windows which many new users might be coming from.