[Vrul]

Not tested but you can try:

hooksecurefunc("CompactUnitFrame_UpdateStatusText", function(self)
	local statusText = self.statusText
	if statusText and statusText:IsShown() then
		if self.optionTable.healthText == "losthealth" and tonumber(statusText:GetText() or "") then
			if not statusText.fontOverridden then
				statusText.fontOverridden = true
				statusText:SetFont("Fonts\\ARIALN.TTF", 16)
				statusText:SetTextColor(0.95, 0.2, 0.2)
			end
		elseif statusText.fontOverridden then
			statusText.fontOverridden = nil
			statusText:SetFont("Fonts\\FRIZQT__.TTF", 12)
			statusText:SetTextColor(0.5, 0.5, 0.5)
		end
	end
end)