I have my main panel in my garage. For the time being I wanted to get a 50 amp breaker installed in the panel and then run #4-3 wire to a junction box in my garage. From there I wanted my electrician to run a #6 wire for a NEMA 14-50 outlet. My plan is to use the 14-50 outlet for the time being and later upgrade the breaker to a higher amp later for a dual Tesla HPWC setup if I get another Tesla. I had an electrician come earlier today for a quote. He said it is against the code to use #4 and #6 in the junction box. I see a number of people suggesting to use #4 from the main panel to for later flexibility. I am confused now. So, should I be only using only #4 everywhere. Also, if I have the junction box, can I wire to a second NEMA 14-50 outlet, assuming I use only one a time?