We should avoid using the old method of scanning the buffs with

 for i = 1, 40 do
         local _, _, _, _, _, _, _, _, _, spellId, _ = UnitAura("player", i, "HELPFUL")
 end

because in SoD and fresh the limit is removed.
A better approach is this

local i = 1
repeat
    local aura = C_UnitAuras.GetBuffDataByIndex ("player", i)
    i = i + 1
until (not aura)

and an even better approach is to just check the buff directly (only for player)

local aura = C_UnitAuras.GetPlayerAuraBySpellID(26481)

Hey @Alessandro-Barbieri this is a great hint, thank you!

I actually don't think using C_UnitAuras.GetPlayerAuraBySpellID is a better aproach as it scales badly with the amount of IDs ECS checks.

But I do like the idea of using C_UnitAuras.GetBuffDataByIndex istead of UnitAura - Are you up for a PR on this change?