REMOVEit replaces the original product image with the new version.
When REMOVEit edits an image, it replaces it on the product. It does not add a second copy next to it.
- The new image is generated and uploaded to your store
- The original image is removed from the product
- The new image is added to the product and moved to the original image's position in the gallery
So if image 1 was edited, the new version is image 1, and your featured image stays in place.
Keep a backup
Because the original is removed from the product, keep your original photo files or export a copy before large runs. See Back up product images before a run for simple ways to do this.