Probably excessive but until this is specifically tested, rather better do more agitations than fewer, and make sure most alkaloids have been pulled... You don't want to waste alkaloids....
You can also buy a magnetic stirrer and make your life easier.
Another thing it would be nice if someone did was a small experiment to, before the first pull, divide the whole basified plant solution in two, and do a quick pull on one, a longer more thorough pull on another. Then retrieve alkaloids from both pulls separately and weigh and let us know

You could even put the two basified mix jars together after that, to make everything easier, as one single pull would already be a good enough comparison to have an idea