Yes, this is true. I can not remember what had happened when I did this, but I can tell you I tried. (With the members)
I suppose I could try right now just to test it again real quick since I am running the latest version of 1.8. EDIT: Just took a peek. PHP-Fusion user_password is under varchar(64) while MyBB is varchar(120). Anything other than the simplicity of the above, I am mindfucked when it comes to MySQL. I design and fornicate.. not develop.