stop automatic modifications to a duplicate

Hmm...if I were you I'd try:
1. Duplicating the table
2. Linking the records together
3. Decide which table I want them to make changes in
4. Create lookups to pull the changed data into the main table
5. Use formulas to differentiate them

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You could also try downloading a CSV of your table now, letting the changes happen, and using a diff tool to see what the changes are too

Thank you for your suggestions! From what I understand and explored  - there is no Airtable solution to just duplicate and modify in one table, not both...? Do you have any recommendation regarding the different tool to be used for pinpointing the changes? Cheers!

Hmm, could I confirm that when you mention duplicating the table, you're referring to this? 

You mentioned the modifications happning to both tables which makes me think I may have misunderstood and you're referring to a synced table?

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re: Do you have any recommendation regarding the different tool to be used for pinpointing the changes?
Ha I was just thinking of using git for this actually, and so in the following screenshot you can see that the "5" got changed to an "A":

You can do this with your code editor of choice, e.g. VSCode and checking the diff between commits