I just bought this house and the kitchen drain keeps overflowing where the dishwasher drain is going into the ABS. I believe the issue is in a clog somewhere in the old galvanized plumbing beneath the house that I am slowly working on replacing. However, the current configuration for the kitchen does not look right to me and the home inspector did not spot any issues. Here are some questions that I would love some help with:

Should the dishwasher drain line be installed into the garbage disposal?

Could (and should) I swap the dishwasher drain line and the garbage disposal line so both the garbage disposal and dishwasher (via garbage disposal) drain to the bottom and the top line becomes a vent?

Thank you all in advance for your help.