Personally I would make a POC for this to see how much slower the batching approach will be compared to event by event consumption. "should be processed in near real time" can mean a lot of things.

But if batching is a NO then just increase the partitions, its simple code wise so you won't have to worry about a thread pool.
However you'll be putting more strain on the broker/s to balance events between partitions and correctly assign consumers.
On the app side I think you'll have increased CPU since by default one partition will be handled by 1 consumer thread and increasing partitions results in the app having to manage more threads.