As mentioned before there are many other points to improve aswell:
Correction of 88-Flak Improvements (summary)
But the importants point in my view is to add more zoom to the sight of the 88-Flakbus since its purpose is to shoot far away airplanes and work out as tanksniper (actually it got some of the worst inzooms of all tanks), adding the sight of the firefly would do great in my opinion
I believe “turret” traverse speed should be increased. The current speed (or rather slowness) is very boring and makes this vehicle extremely vulnerable. You are unable to quickly react to basically anything.
also reduce it to BR3, as its on the powerlevel of dicker max who is barely playable at BR3.
the flakbusses AA capabilities also need to be improved (while keeping its ground strength), then we will have a nice and worth buying vehicle.
its important for HA that the flakbus works well, as it was one of the most important weapons of the 40/41 campaigns, dealing with fortified positions and some of the heavy armored french and soviet tanks
edit: i have a dicker max and cant really use him in the lineup as panzer 4 J is just better, same thing goes for flakbus, its overall worse than a strong all round tank and needs its gimmicks to really work well to be playable.
When they fix the time fuse round I will buy that thing
88mm flak bus should be tier 3