Jackson has its problems, but give how it shuts down Ostheer T3, I don't think it needs buffs currently.
It'd be like buffing the Ost panther because it nullifies Soviet T3, oh wait.
It needs a pen buff, because it's absolute shit against anything that isn't a medium tank.
Not even saying a huge pen buff, it's a 240dmg cannon a slight buff to make it a tad bit more consistent, as it is it fails more than it succeeds, the supposed turreted super squishy tank destroyer can't destroy tanks and it's a drain of resources on any other role.
Its main antagonist (the OKW panther) simply laughs at it, its function is more that of giving the panther vet since it can't chase it because of shot blockers/panzerschrecks/pak43/raketen whatever, can't penetrate it at vet 2 (unless HVAP is used, but there lies the problem, you need penetrations to get experience) and even if you are in a good spot to kill the panther it just needs vet 1 to activate the afterburners and go at incredible speed with a ridiculous -50% received accuracy bonus, it's just silly.