Sorry to hear about your ACL injury.

I have personal experience with this.  Nearly the same as you (mine was the front left leg as well).  I was able to board for a couple seasons, mostly with a brace.  I can say that my knee was pretty stable 99.9% of the time, but every once in a while it would buckle and hurt like crap.  I could keep the knee protected most of the time by keeping my knees bent ALL the time, but that can get exhausting; but overall, the more bend your bad knee is, the more protected it is. 

The challenge is that you cannot stay in perfect balance all the time due to low light situations, traffic, unexpected obstacles, and fatigue.  Then there is the chairlift which really torques the front knee, especially while LOADING the lift.

The decision to snowboard with a fully torn ACL is up to you, but be aware that if it buckles while riding, you will not only have the pain to deal with, but also the possibility of tearing precious cartilage and/or damaging other ligaments.   

My knee is fully repaired now (hamstring graft method) and holds very strong.  Actually stronger than I thought, almost like new.

I am not going to tell you what to do, but I can say this.  I am older now (37) and both my knees suck.  My left has been repaired surgically twice (once to rebuild ACL and once to repair torn cartilage) and my right knee is worn all the way down due to favoring the left one for so long.  I wish I would have taken better care of them when I was younger!

Alright.  Have fun and stay safe bro!