Reopen rails engine model in app

reopen_engine_model.rb

# Rails 3.2.6

# my_engine/app/models/user.rb
# Define class in engine
class User < ActiveRecord::Base
 #methods here 
end


# my_rails_app/app/models/user.rb
# Require the engine model first and then reopen it to add new methods, associations, etc
require MyEngine::Engine.root.join('app', 'models', 'user')
class User
  #new methods here
end

Rather than reopen the classes, I think I am going to implore this strategy.
https://gist.github.com/3132025

From your time with Rails Engines, will this cause problems in the long run?

The advice I have gotten so far says no.
https://groups.google.com/forum/?fromgroups#!topic/rubyonrails-core/jy2dQ0BQhnM