Hi,
Great question! On Editor X, you can modify individual repeater items using Corvid (our development platform) we have some exposed methods on the Repeater API.
You can find more information here: https://www.wix.com/corvid/reference/$w/repeater
If you have specific questions about writing the code, then we recommend that you use the Corvid Forum for help: https://www.wix.com/corvid/forum