The question was not coming out from curiosity, but from trying to understand what you are after, and trying to be helpful.
I dont know why its so difficult to understand "I need to convert multiple scatters into mesh", but ok
Converting Scatter geometry to Max, even for one scatter object, can be very taxing for the scene - even if the instanced mesh can be simple, creating a large number of objects in the scene, which the conversion does, will most probably lead to scene freeze. I am not talking about hundreds of scatters. This will surely be the same for ForestPack conversion (if it does not attach all the scattered geometry into one object).
You are assuming that because of this, we dont need to convert scatters on mesh? Of course that we would consider that this will provoque frezzes or even crashes, but I wouldnt mind if this works in the end, ForestPack takes some cautions to this, placing new objects on new layer and displays as box or even hiding them, but it can be done.
Unfortunately there is not way to do this in batch. I was trying to create a batch script for you with maxscript for this, but seems there is no way to do it.
This will be registered as a feature request, but this is not something that is regularly done, I believe.
If having the geometry "on place" was the end goal (given the screenshots, I think these are linear scatters), maybe other ways of modeling could be beneficial, e.g. the array modifier (which has solid scattering options too), which would later be easily converted into mesh.
I don't see any other option than to convert them one by one, I am afraid.
Thank u to take your time to try this, fortunately Frood achieve this beautifuly, here are some suggestions from Corona Developers.
Use the script that Frood wrote, test it, make it your own if you will and create a button on the toolbar, put some advice that will provoque frezzes or crashes or whatever. But please add it!!!
Here is the ressult, there were 240 scatters, it didnt took too much time to convert them and it didnt frezzes or crashes.