You can spawn maintank and main assist frames with :
local tank = oUF:Spawn('header', 'oUF_MainTank')
tank:SetManyAttributes('showRaid', true, 'groupFilter', 'MAINTANK', 'yOffset', -5)
tank:SetPoint('BOTTOMRIGHT', UIParent, 'BOTTOMRIGHT',-10, 20)
tank:Show()
local assist = oUF:Spawn('header', 'oUF_MainAssist')
assist:SetManyAttributes('showRaid', true, 'groupFilter', 'MAINASSIST', 'yOffset', -5)
assist:SetPoint('BOTTOM', tank, 'TOP', 0, 10)
assist:Show()
I'm using it like so :
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