[siweia]

Thank you Rainrider, you wake me up.

local function preUpdateForBolster(element)
	element.bolster = 0
	element.bolsterIndex = nil
end

local function customFilterForBolster(element, _, button, name, _, _, _, _, _, _, _, _, _, spellID)
	if name and spellID == 209859 then
		element.bolster = element.bolster + 1
		if not element.bolsterIndex then
			element.bolsterIndex = button
			return true
		end
	end
end

local function postUpdateForBolster(element)
	if not element.bolsterIndex then return end
	for _, button in pairs(element) do
		if button == element.bolsterIndex then
			button.count:SetText(element.bolster)
			return
		end
	end
end