On your vehicle, the battery IS toast as previously mentioned. If you want to keep testing Zombieverter regardless, you need to adjust params to keep the setup happy, meaning you need ways to limit the max current draw to mitigate the voltage sag to levels the battery can handle.
My experience is on Zombieverter 2.22A official and 2.23 testing, just to tag this bit of information for anyone finding this post with search
Unlike the Leaf VCU, Zombieverter DOES NOT adjust the max torque request based on what Leaf BMS tells is allowed, so that's probably one of the reasons you can have a smooth accel and drive with Leaf VCU but not with Zombieverter.
On the latest params you uploaded, try to reduce throtramp (1 or lower) and put the throtramprpm to something close to or above the max rpm limit.
You can see on the plot that at 1800rpm, throtramp stops and then torque/speed spikes
Also test what adjusting throtmax between for example 50-70% does to the feel.
If you want to understand better how Leaf VCU controls the torque request, you might want to make few CAN logs so you can analyze for example how the Leaf VCU handles control when the battery is in such bad condition as yours is.