No it is better in your pump tank if you can make it work there. The 2nd chamber of your septic tank will accumulate some sludge that was not trapped into the 1st chamber, and all of that sludge will enter your septic field when it is stirred up by an aerator.
I don't like aeration unless it is in the D Box to directly aerate what goes into the laterals. All sludge should be contained within the septic tank and not be stirred up to be sent to the field.