I prefer a model in which the eternal Son of God was already Lord and Servant, Lion and Little Child, Rock and Tender Shoot, Shepherd and Lamb in the Old Testament period. That means His lambness and suffering did not begin on the Cross or even in his Incarnation.
God is love, and anyone who loves gets hurt. That means that the Eternal Son of God inevitably suffers when He wants to go for a walk with us and we prefer to hide like Adam and Eve in the Garden of Eden. That takes His sufferings at least back to the first humans in the image of God.
But God is Trinitarian. So the Eternal Father also suffers whenever we refuse to honour Him as God, or we turn to others instead of running to Him as little children. Similarly the Holy Spirit has from the Old Testament period suffered when humans prefer to choose their own wisdom to His inspiration, or rely on their own strength instead of His power.
That suggests that on the cross (in Jerusalem on the first Good Friday) the eternal love-suffering of all three Persons of the Trinity was made visible for all the world to see in a few hours of space-time.
How do we settle between a model of the atonement in which all the atoning suffering was done on Good Friday, or Christ's suffering began with the Incarnation, or the cross is an eternal expression of the very heart of God?
As I read the Bible I find that the Father is hurt as a loving parent by our indifference, but still keeps loving us. The Holy Spirit is hurt when we choose our own wisdom to His, but He still keeps loving us. And the Son is hurt when we refuse to walk with Him, enjoy His friendship, and serve Him as Lord, but He still keeps loving us. That is what the eternal heart of God is like.