It's cool that you are looking for ways to improve. I always do the same. I would say to transplant a larger fabric pot when ready. I don't like plastic pots anymore. Getting root bound sucks. Since you are growing outside the plant may turn into a monster and that pot could end up being too small.
It looks like there is a bit of yellowing and it does not look bad but it could be a sign to increase nutrients a bit. A healthy plant will be totally solid deep rich green.
looks healthy. 50 gallon pot? thats quite excessive if you ask me.. i think a 30 gallon would do just perfect. any perlite in your soil? if not i would recommend mixing some in with it. other than that it looks healthy!