Fading animation

[Benalish]

Hello there. I'm trying to copy the same animation as the buffs when are about to expire.
This is my attempt:

local f = CreateFrame('Button', 'MyButtonName', UIParent)
f:SetPoint('CENTER')
f:SetSize(128, 128)
 
local tex = f:CreateTexture(nil, "BACKGROUND")
tex:SetAllPoints()
tex:SetTexture(1, 1, 1, 0.5)
 
f.flasher = f:CreateAnimationGroup()
 
f.flasher:SetLooping("BOUNCE")
 
f.flasher:SetScript(
    "OnFinished",
    function(self, requested)
        if requested then
            self:Hide()
        end
    end
)
 
local fadeIn = f.flasher:CreateAnimation("Alpha")
fadeIn:SetDuration(0.5)
fadeIn:SetChange(0.5)
fadeIn:SetOrder(1)
 
local fadeOut = f.flasher:CreateAnimation("Alpha")
fadeOut:SetDuration(0.5)
fadeOut:SetChange(-0.5)
fadeOut:SetOrder(2)
fadeOut:SetEndDelay(1)
 
f.flasher:Play()

The animation from "fadeIn" to "fadeOut" works well, but the transition from "fadeOut" to "fadeIn" seems too sharp.

Any suggestions?