If you don't mind not being able to scroll things (i.e. Navigator window, etc.) then one can copy paste the code below to remap the scroll wheel altogether. I think this is simpler as this will work no matter how many charts are open and also offline charts.
Inserted Code
#IfWinActive ahk_exe terminal.exe WheelUp:: Send {NumpadAdd} Return WheelDown:: Send {NumpadSub} Return
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