Yeah it seems easier in general but then again maybe that's the solo multipliers, not sure what they meant exactly but that felt a bit easier. Got to final wave on HoE solo as Firebug without much effort! Using the DoT tree as well, that seems to be a bit of a monster tree! I will say though that the slow would make more sense in the left tree as the right tree seems to support "here and now" type damage, even though it's not the damage tree. All I'm saying is the slow would probably be better used with Napalm or BBQ to go with the duration, if that's really the route it has to go. Ground Fires should make actual ground fires last longer rather than slow enemies in it (like Flarotov did). I'll probably add to this in the Firebug thread after a bit more playing.
The composition of waves and the ability to dodge/block is keeping up with it though, the dodge/block stuff is great as I always felt they just attacked linearly without thought, this adds something that was needed. Picking up just a flamethrower only to have the wave throw 3+ Husks at me was a fun surprise to say the least!
Can I also just say that the thick smoke effects you've added to the flamethrower are really nice, decent improvement! If I had one bit of feedback about it though it'd be that the "speed" of the fire animation is the same (Feels kinda choppy or fast-moving, like it's one of the 200fps guns or something. The fire dances too fast and I feel the naked eye misses a fair bit of it). Was a fantastic surprise in this update though and I'd say the fire is halfway along to becoming like Rising Storm!
I would keep going but I've just realised this probably isn't the place eh?