We have the following SharePoint Choice field which allow fill-in value:-

Then we created a canvas app >> where the above field will be mapped as a combo box, so i have did these modifications:-
1) i removed the mapped combo box and enter radio button with static values representing the standards options as per the above field definition.
2) I added a checkbox and free text to allow the user to either select a radio option or enter a manual value, as follow:-

3) finally i updated the Update property of the card, as follow:-
If(varManualAdd2,{Value : TextInput2.Text},Radio1.Selected)
now this is working for creating a new item.. but since i am using the same form to edit items.. so how i can do the following:-
1) when i retrieve the list item and define it inside Item property for the form:-
If(IsBlank(varRecord),Defaults('Online Credit Request'),varRecord)
how i can map the value of this Choice field>> to get the related Radio option selected
2) incase the current value does not match any of the static Radio choices, how to enter the value inside the free text?
Any advice ?
Thanks