Hint 1: 5 DU buff beam to max DU.

After placing each buff beam, upgrade it two times.

Only fully AFKable after buffs/auras are upgraded and using a CTRL+G macro:

#MaxThreadsPerHotkey 2
#MaxHotkeysPerInterval 20 
#SingleInstance Force
#IfWinActive, Dungeon Defenders
#NoEnv
#Persistent
SendMode Input

; Automatically Press CTRL+G after pressing F10
F10::
    toggle := !toggle

    If (!toggle) {
        ToolTip
    }
    Else {
        Tooltip, Auto-Advance On (press F10 to stop), 0, 0
    }

    Loop {
        If (!toggle) {
            Break
        }
        ControlSend, , ^&g, ahk_exe DunDefGame.exe
        sleep 1000
    }
return