[kurapica.igas]

My codes is here, it's an interface so I used it for raid panel and bag containers.

Here is a simple one, I don't do a test, since the group header settings is ignored :

local panel = CreateFrame("Frame", "ResizablePanel", UIParent, "SecureFrameTemplate")
 
-- Shortcut
panel.Execute = SecureHandlerExecute
panel.SetFrameRef = SecureHandlerSetFrameRef
panel.WrapScript = function (self, frame, script, preBody, postBody)
    SecureHandlerWrapScript(frame, script, self, preBody, postBody)
end
 
-- Grid Settings
panel:SetAttribute("WIDTH", 100)    -- Unit Frame width
panel:SetAttribute("HEIGHT", 48)    -- Unit Frame height
panel:SetAttribute("HSPACE", 2)     -- horizontal spacing
panel:SetAttribute("VSPACE", 2)     -- vertical spacing
panel:SetAttribute("ROWCNT", 5)     -- Row counts
panel:SetAttribute("COLCNT", 4)     -- Col counts
 
panel:Execute[[
    Manager = self  -- keep self to avoid some bug, I don't know if it still existed
 
    _UnitFrames = newtable()  -- where we keep all unit frames
 
    UpdatePanelSize = [=[
        -- For simple, skip several settings like margin, orientation
        local rowcnt = Manager:GetAttribute("ROWCNT")
        local colcnt = Manager:GetAttribute("COLCNT")
        local width  = Manager:GetAttribute("WIDTH")
        local height = Manager:GetAttribute("HEIGHT")
        local vspace = Manager:GetAttribute("VSPACE")
        local hspace = Manager:GetAttribute("HSPACE")
 
        local count  = 0
 
        -- Re-position unit frames based on visiblity
        for i = 1, #_UnitFrames do
            local frm = _UnitFrames[i]
            if frm:IsShown() then
                -- orientation is vertical first
                local posX = (floor(count / rowcnt)) * (width + hspace)
                local posY = (count % rowcnt) * (height + vspace)
 
                frm:SetWidth(width)
                frm:SetHeight(height)
                frm:ClearAllPoints()
        
                -- from top to bottom
                frm:SetPoint("TOP", Manager, "TOP", 0, - posY)
 
                -- from left to right
                frm:SetPoint("LEFT", Manager, "LEFT", posX, 0)
 
                count = count + 1
            end
        end
 
        -- Re-size the Manager
        local maxcol = ceil(count / rowcnt)
        local maxrow = maxcol == 1 and count or rowcnt
 
        if maxrow > 0 and maxcol > 0 then
            Manager:SetWidth(maxcol * width + (maxcol - 1) * hspace)
            Manager:SetHeight(maxrow * height + (maxrow - 1) * vspace)
        else
            -- You also can use Hide here
            Manager:SetWidth(1)
            Manager:SetHeight(1)
        end
    ]=]
]]
 
-- For simple I generate those unit frames directly
-- Your is generated by the ouf
for i = 1, panel:GetAttribute("ROWCNT") do
    for j = i , panel:GetAttribute("COLCNT") do
        local unitframe = CreateFrame("Button", "ResizablePanel_" .. i .. "_" .. j, panel, "SecureActionButtonTemplate")
        
        -- Register the unitframe
        panel:SetFrameRef("unitframe", unitframe)
        panel:Execute[[tinsert(_UnitFrames, Manager:GetFrameRef("unitframe"))]]
 
        -- Wrap the unitframe's show/hide
        -- So the secure UpdatePanelSize can be run based on the unitframe's visiblity
        panel:WrapScript(unitframe, "OnShow", [[Manager:RunFor(self, UpdatePanelSize)]])
        panel:WrapScript(unitframe, "OnHide", [[Manager:RunFor(self, UpdatePanelSize)]])
    end
end
 
-- Force updating
Manager:Execute[[Manager:Run(UpdatePanelSize)]]

Also there is a topic discuss about Run secure code based on the group header system, you can find my answer from #12.

I don't know if it can be combined with the Ouf, you may have a try.