The approach you mentioned Copy Data From a Data page: -
The common trait of this pattern is that the case needs to have access to the most current data. For example, if the account holder’s phone number changes we want that to be reflected when the data is accessed from the case. Usually, the data loaded comes from an external data source.
One part of this pattern that differs from application to application is when the data needs to be refreshed. Under the refresh strategy section of Data page, you need to balance application performance with data accuracy. If we select reload once per interaction in the Data page, the lookup or service call can be called once for each user interaction.
Ideally if you want to pick the latest data every time you refer that property, you should go with "Refer to Data page" instead of "Copy From Data Page". From your question, it is clear that you are also aware of this. So what I would like to know here is: what is the complication that you have with your use-case because of which you cannot use 'Refer to Data Page'.
You can add screenshots if required, I can try to help by investing some time.