The biggest one I was on in Arizona was called the Castle Fire, outside of Phoenix in the late 70's. Did shifts 30 days in a row, it was so hot that the only shade was provided by outhouses, back when we didn't carry dome tents, etc. but slept in paper sleeping bags. Nowadays, they get two days off after 14 days, but back then thrashing the people was not a big concern. I jumped at the chance to get on a helitack crew after that.
Much of the pyrocumulus stuff is cloud to cloud lightning, and doesn't often do positive ground strikes, but it would ground the aircraft sometimes.
If you look at a big convection column, there will often be a zone at the top where the smoke turns into an ice cloud, it looks like bright white on top of grayish smoke below. That is where the friction and electrical charges get organized enough for lightning.