In chapter 5 of his Calvin and the Reformed Tradition (Baker, 2012), Richard Muller takes his reader through the reflections of Bishop Davenant, one of the English Delegation to the Synod of Dordt, who wrote elaborately on this universalism. Davenant was at pains to stress that this death is not a salvific universalism, as regards the question of those who fully benefit from it. Nonetheless everyone benefits from it, to some degree or another. Whereas Calvin attribute common operations to the Holy Spirit, Davenant attributes them to Christ's death.
In the very appointment or ordination of a Redeemer, God had some regard of common love towards me, which he had not towards devils. Which will appear further if we consider what this redemption is. It is, then, the payment of the just price due for us captives, not that we should actually be delivered on the payment of the price, but that we should be delivered as soon as we believe in the Redeemer. This is that ordination of the death of Christ or of a satisfactory price, which flowed from the common love of God to all mankind, and therefore, it is rightly declared to be extended, under this condition, from us to all men individually. And to this we think that celebrated passage refers, John 3.16, God so love the world etc.
But now as to what relates to that secret and more special love, with which God embraces the elect, far be it from us to deny that the death and merit of Christ is a special gift to be effectually and infallibly applied in a special way to the elect, who are to be redeemed and saved through his special love. Therefore we attribute ti that common love, with which God waits upon the human race, that he was willing to appoint such a Redeemer, through whose death and satisfaction any one provided he should believe in him, might be absolved from his sins, Acts 13. 38. But we think that is to be attributed to his special good pleasure, with which he embraces the elect alone, that from the death and merit of this appointed and ordained Redeemer, he should determine to give to certain individual persons effectually and infallibly, faith, and eternal life. (388-9)
I…affirm that God in sending the Redeemer was willing to manifest to the world both these kinds of love; namely, that common love of the human race, which we call philanthropy, and that special and secret love, which we call good pleasure.’ (388)