People are sick of people complaining (not that you are) about the beta not working or their phone being bricked because they are not going about the beta "legally". If you don't want to pay the $99 to join the dev program, then you need to wait for at least the GM to be released. Otherwise pay for the program and do it the right way. Find some friends to split the cost, join an actual developers team, whatever, just do it the right way.
To answer your question, try it out. If it works great, if not (which it probably won't) you will have to go through the steps DFU, etc. to fix it. Eventually the betas will stop being supported and your phone will be bricked anyway.