I have a bulging (not fully herniated) cervical disc from MMA. Snowboarding has actually been fine for me (knock on wood). I don't bomb at mach 5 and tend to hit smaller park features, though.
That said, my injury is a good 5 years old at this point. I did the whole PT thing back then as well. Unfortunately, while I can still ride fine I have not been in any fights since the injury - just not really worth it.
As with anything else, stretching and getting warmed up is key. I personally tend to forget this when riding, though I'm religious about it before lifting or any kind of cardio (including sparring).
This year, I'm thinking of investing in a full suite of protective gear (spine, knees, helmet for sure). The price tag is super annoying, but ultimately if it helps it's completely worth it.
Some general tips that have helped me :
- Good nutrition : anti inflammatory, lots of fruits and vegetables, not too much alcohol while riding
- Stretching / warm up : super important, IMO
- Less risky features : personally, I don't do rails anymore, and stick to 10-20 foot booters.
- Sleep : this really can't be overstated.