I'm curious about how the mech will interact with the rest of the kit. You have to keep in mind that there's no ammunition to weave anymore based on the UI and what we saw, which does at least combat the clipping issues somewhat, and it seems likely the new skills shown are intended to replace that as our filler. I'm hoping that means you're not encouraged to use any of those new abilities under Wildfire in order to set up the mech on the next Wildfire, akin to how SMN currently delays activating Bahamut till their next Aetherflow rotation but is also encouraged to burn DWT and their initial Aetherflow asap in order to accelerate him out. Otherwise it would likely be worse.

While the heat gauge is there it's notable that nothing that we saw other than the standard bullets and Barrel Stabilizer generated it. One would hope that means Overheat is gone, but we can't rule that out entirely yet either as they don't actually cap heat in the trailer. At the very least, you wouldn't be able to Wildfire and Overheat at the same time, since it appears that Wildfire costs heat now.

All in all it's a hot mess till we get our hands on it.