Changing detail page on old listing. Will this trigger GS1 UPC check?

I have several old listings that have ebay UPC’s. I have yet to update them to GS1 UPC’s but I need to make a change to my detail page (swap out one image). Will making this change trigger the GS1 check? I’ve read several instances of this occurring, although anecdotal.

1. Have any of you successfully made changes to your old listings with non GS1 UPC’s?

2. Should I make this change through a flat file (wishful thinking that it will avoid GS1 check)?

Your advice is greatly appreciated!