During the reigns of Edward VI and Queen Mary, it appears Baldwin played an occasional role in the production of theatrical exhibitions at court, while continuing to work at the printing shop.
He is probably the William Baldwin who was ordained deacon by Archbishop Grindal in 1563; the same man was described as a minister in the 1587 Mirror for Magistrates, and was noted to have given up printing for an appointment in the church, viz.
A further possible identification is in Stowe's account in Historical Memoranda of one Baldwin preaching at Paul's Cross in September 1563, who died a week later of the plague.
The 1547 A Treatise of Morall Phylosophie, contayning the Sayinges of the Wyse, authored by Baldwin and printed by Whitchurch, was a small black-letter octavo of 142 leaves.
In 1547 Baldwin prefixed a copy of verses to a work by Christopher Langton (1521–1578), the Treatise ordrely declaring the Principall Partes of Physick.