HI @gjayne84,
Do you want to populate the Person field within your Edit form automatically based on the selected approver name within the Choice field?
I have made a test on my side, please take a try with the following workaround:

Firstly, you need to add a Office 365 Users connection within your app.
Within the Edit form (SharePointForm1), set the DefaultSelectedItems property of the Combo Box control within the ApproverPersonField Data card to following:
If(
SharePointForm1.Mode=FormMode.New,
{
Claims: "i:0#.f|membership|" & Lower(LookUp(Office365Users.SearchUser(),DisplayName = DataCardValue3.Selected.Value,Mail)),
DisplayName: DataCardValue3.Selected.Value,
Email: LookUp(Office365Users.SearchUser(),DisplayName = DataCardValue3.Selected.Value,Mail),
Department:"",
JobTitle:"",
Picture: ""
},
Parent.Default
)
Note: The DataCardValue3 represents the Combo Box control within the ApproverChoiceField Data card.
On your side, you shoukld type:
If(
SharePointForm1.Mode=FormMode.New,
{
Claims: "i:0#.f|membership|" & Lower(LookUp(Office365Users.SearchUser(),DisplayName = YourApproverChoiceComboBox.Selected.Value,Mail)),
DisplayName: DataCardValue3.Selected.Value,
Email: LookUp(Office365Users.SearchUser(),DisplayName = YourApproverChoiceComboBox.Selected.Value,Mail),
Department:"",
JobTitle:"",
Picture: ""
},
Parent.Default
)
Please check the attached GIF screenshot for more details:
Best regards,
Kris