Clipboard Queue - Keep multiple clipboards at the ready or paste them in a sequential order!

ClipQueue.ahk

/* 
   ___ _ _         ____                       
  / __\ (_)_ __   /___ \_   _  ___ _   _  ___ 
 / /  | | | '_ \ //  / / | | |/ _ \ | | |/ _ \
/ /___| | | |_) / \_/ /| |_| |  __/ |_| |  __/
\____/|_|_| .__/\___,_\ \__,_|\___|\__,_|\___|
          |_|coded by errorseven @ 8/26/2016                                 
 
Usage: 
    
    Ctrl + V            Pastes based on Mode and contents of your ClipQueue
    Ctrl + <            Move Queue Pointer Left
    Ctrl + >            Move Queue Pointer Right
    Ctrl + Alt + M      Select used with Pointer, Queue Pops 1st Element Queue.
    Ctrl + Alt + X      Clear ClipQueue

*/

clipQueue := [], p := 1
clipPrevious := ""
Mode := "Select"

setTimer, checkClipboard, 100

$^v::
    setTimer, checkClipboard, Off
    
    if (Mode == "Select") 
        clipboard := clipQueue[p]      
    else if (Mode == "Queue") && (clipQueue.length()) 
        clipboard := clipQueue.removeAt(1)
 
    send, {Ctrl down}v{Ctrl Up}
    clipboard := clipPrevious
    setTimer, checkClipboard, On
return

^!m::
    Mode := Mode == "Select"  
         ? "Queue"
         : "Select"
    
    TrayTip, Mode, % "Set to " Mode,,500
return 

^!x::clipQueue := [] 

^,::
    p := p > 1 ? p - 1 : clipQueue.MaxIndex()
    tooltip, % clipQueue[p]
    SetTimer, RemoveToolTip, 500
return

^.::
    p := p < clipQueue.MaxIndex() ? p + 1 : 1
    tooltip, % clipQueue[p]
    SetTimer, RemoveToolTip, 500
return

checkClipboard:
    if (clipboard != clipPrevious) {
        clipQueue.push(clipboard)
        clipPrevious := clipboard 
        p := clipQueue.maxindex()
    }
return

RemoveToolTip:  
     SetTimer, RemoveToolTip, Off    
     ToolTip    
return

It appears to me that the checkClipboard timer will run every 100ms, always (not just when invoking this script). Not knowing much about AHK I accept that this could well be necessary, but it is unfortunate. Am I reading it wrong?