Hi Yev,
PennController always gives focus to the most recently added TextInput element. If at one point in your trial, you want focus to go to a given TextInput element, you can use the Function element to execute some javascript code during runtime:
newTrial(
newTextInput("first").print()
,
newTextInput("second").print()
,
newFunction( ()=>document.querySelector(".PennController-first").focus() ).call()
,
newButton("Next").print().wait()
)
Jeremy