i made a small modification for loading data, when attributes are missing in firebase objects. 

when changing your schema of object. eg. adding a field/attribute, then the knockoutFire function exits with error, because the "map" cannot be matched with the data coming from the database. 
with this   

if( typeof self() == 'null' || options.map == true ) return; 

it will still work, and one can read and write data.

you can see demo at: 
http://www.holomind.de/todos/

eg. i changed my objects to also have attribute "user": 
-ItIOcbx80cg-gxTdvkQ

    content: some text
    isdone: 1
    project: project-1
    user: user1

-ItIOeW3u0KdUKtGD_1C

    content: other test
    isdone: 0
    project: project-1

=> here the user: user-1 is missing, and had caused problems before. 
with this extra line it works. and data can be loaded and saved, and the missing values will be added automatically.