You'll just need to make sure listings' SKUs match so that they can be linked to each other (also works at the variant level!). The SKUs can be a mix of upper and lower case and still match. Because the SKU is the only field that needs to match, this means you can still have different titles, descriptions, images, etc. for each of your listings. For example, if your sales channels are Etsy, Shopify, and Square, then the respective listings can have this info and match/link up:
ON SALE concrete new planter, perfect gift
Concrete Planter for Indoor Plants
Trunk is also smart enough to pick up on any SKU changes. For example, if you don't have any SKUs yet, you can simply update the SKU on your sales channel's website/app and Trunk will automatically pick up on it and link things appropriately. When adding new listings to your sales channels, the only thing you need to make sure to do is make sure SKUs match and Trunk will do the rest.
If you're new to SKUs, they are identifiers for tracking your inventory internally. Each sales channel platform we integrate with supports SKUs.