You keep repeating this and yet you've never really offered anything resembling a concrete proposal on how to actually "make it useful", while considering its performance across multiple game modes, outside of "just put it into some meh commanders", again without any details on which ones and what it should replace then (and removing Panzer Authorization but that was specifically decided against already). Problem-centric attitude gets us nowhere. Come up with proper solutions instead.
Also in regards to the Hetzer frontally wiping an ATG; the trick is to attack ground the gun for 1-2 flame bursts and then back up and let the high DOT damage kill the crew or at least force it to retreat on low health, which is easy to achieve when the Hetzer is supported by some infantry. And hope that its 15 target size allows it to dodge a shell or two. I doubt it can reliably take on double ATGs though, but I wouldn't expect a 90 fuel vehicle to do so anyway.
On some maps, the Hetzer is already difficult to deal with. For example, the south part of Red Ball has enough site-blockers that you can't have 2 ATG's per lane, and a single ATG plus infantry can't deal with a Hetzer. I've played against a couple players who were top 50 in 4v4's that used Hetzers, normally backed up with 2 raketens so you couldn't use a Sherman or T34/76 against it. It's much harder to fight it if you've been behind in fuel and don't have a TD.
If I had any complaints about Feuerstorm, it would be that I would like to see the off-map arty reliably wipe howitzers. It should and right now doesn't seem very good for the cost.