Ash Prime Weak to Toxic in SP?

I've been running Ash Prime in Steel Path just fine, it's a blast. The only thing I keep running into (literally) are toxic clouds that kill me pretty quickly. Other elements don't affect Ash that way, just the toxin. Should I mod him for resistance to it or just use Rolling Guard/Adaptation? Rolling Guard has been working okay but I still have to stay away from toxin clouds as much as possible.