[SDPhantom]

There are a couple issues I'm seeing. First of all, it's not a good idea to replace the metatable of a frame unless you absolutely need to. Also, you're creating an extra frame that you're not using for any specific purpose that needs a frame. Taking these issues in hand and some further optimizations, here is the code that I'd propose.

--  Settings
local MaxDisplay=5;
local UpdateSpeed=1;
 
--  Init table
local AddonData={};
for i=1,GetNumAddOns() do
    AddonData[i]={ID=i,Name=GetAddOnInfo(i),Value=0};
end
 
--  Format time func
local function AddCPULine(tooltip,name,secs)
    if secs > 3600 then
        tooltip:AddDoubleLine(name,format('%.2f h',secs/3600),1,1,1,1,0.2,0.2);
    elseif secs > 60 then
        tooltip:AddDoubleLine(name,format('%.2f m',secs/60),1,1,1,1,1,0.2);
    elseif secs >= 1 then
        tooltip:AddDoubleLine(name,format('%.1f s',secs),1,1,1,0.2,1,0.2);
    elseif secs > 0 then
        tooltip:AddDoubleLine(name,format('%.1f ms',secs*1000),1,1,1,0.2,1,0.2);
    end
end
 
--  Format memory func
local function AddMemoryLine(tooltip,name, size)
    if size>1000 then
        tooltip:AddDoubleLine(name,format('%.2f mb',size/1000),1,1,1,1,1,0.2);
    elseif size>0 then
        tooltip:AddDoubleLine(name,format('%.2f kb',size),1,1,1,0.2,1,0.2);
    end
end
 
--  GameTooltip calls this OnUpdate if it exists
local LastUpdate=0;
function MiniMapTrackingButton:UpdateTooltip()
--  FPS and latency
    local down,up,latency=GetNetStats();
    local fps=format('FPS: %.1f',GetFramerate());
    local net=format('Ping: %d ms',latency);
 
    GameTooltip:SetOwner(self,"ANCHOR_BOTTOMLEFT",0,self:GetHeight());
    GameTooltip:ClearLines();
    GameTooltip:AddDoubleLine(fps,net,1,1,1,1,1,1);
    GameTooltip:AddLine("--------------------------------------------------");
 
--  Update throttle
    local now=GetTime();
    if now-LastUpdate>UpdateSpeed then
        local watchingCPU=(GetCVar("scriptProfile")=="1" and not IsModifierKeyDown());
 
--      Request game client to update internal cache
        if watchingCPU then
            UpdateAddOnCPUUsage();
        else
            UpdateAddOnMemoryUsage();
        end
 
--      Update data
        local total=0;
        for i,j in ipairs(AddonData) do
            local val=(watchingCPU and GetAddOnCPUUsage(j.ID)/1000 or GetAddOnMemoryUsage(j.ID));
            j.Value=val;
            total=total+val;
        end
 
--      Sort data
        for i=1,#AddonData-1 do
            local max,id=0;
            for j=i+1,#AddonData do
                local val=AddonData[j].Value;
                if val>max then max,id=val,j; end
            end
 
            if AddonData[i].Value<max then
                AddonData[i],AddonData[id]=AddonData[id],AddonData[i];
            end
        end
 
        if watchingCPU then
            GameTooltip:AddLine("Addon CPU Usage");
            GameTooltip:AddLine("--------------------------------------------------");
 
            for i,j in ipairs(AddonData) do
                if i>MaxDisplay then break; end
                AddCPULine(GameTooltip,j.Name,j.Value);
            end
            GameTooltip:AddLine("--------------------------------------------------");
            AddCPULine(GameTooltip,"Total",total);
        else
            GameTooltip:AddLine("Addon Memory Usage");
            GameTooltip:AddLine("--------------------------------------------------");
 
            for i,j in ipairs(AddonData) do
                if i>MaxDisplay then break; end
                AddMemoryLine(GameTooltip,j.Name,j.Value);
            end
            GameTooltip:AddLine("--------------------------------------------------");
            AddMemoryLine(GameTooltip,"Total",total);
        end
    end
    GameTooltip:Show()
end
 
MiniMapTrackingButton:SetScript("OnEnter",function(self)
    GameTooltip:SetOwner(self,"ANCHOR_BOTTOMLEFT",0,self:GetHeight());
    self:UpdateTooltip();
end);
 
MiniMapTrackingButton:SetScript("OnLeave",function() GameTooltip:Hide(); end);