The Bible scholars involved in the translating of the English Standard Version say this:
Acts 20:28 (ESV): “to care for the church of God, which he obtained with his own blood.” Refers to the blood of Christ... the blood of God’s own Son, which would be a legitimate alternative reading of the Greek. Some Greek manuscripts read “the church of the Lord.”
The Bible scholars involved in the translating of the New International Version say this:
Acts 20:28 (NIV): “Be shepherds of the church of God, which he bought with his own blood.” Literally “the blood of his own one” referring to his own Son. Many manuscripts say the church of the Lord.
The Bible scholars involved in the translating of the New Living Translation say this:
Acts 20:28 (NLT): “Feed and shepherd God’s flock – his church purchased with his own blood.” Or “with the blood of his own [Son]”
I have no idea whether those Bible scholars and translators would wish to be labelled as Evangelical Christians, though. However, they are in agreement that there is nothing wrong in translating the Greek into “the blood of God’s own Son” or similar.
One Bible translation (the New World Translation) renders Acts 20:28 as “the congregation of God, which he purchased with the blood of his own Son.” The Bible translators are not named but it is highly unlikely that they would wish to be identified as either Evangelical Protestants or Evangelical Catholics. They are, however, unanimously anti-Trinitarian.
As for Iglesia ni Cristo, they believe that Jesus was created by God the Father and is not a deity and the Holy Spirit is the power of God and also not a deity, being sent by God the Father and Jesus Christ to guide God's people. However, the manner in which that one verse in the Bible is translated neither proves nor disproves the Trinity, although it is understandable why anti-Trinitarians prefer the Lamsa translation of Acts 20:28.