Omnivore allows you to modify product titles individually, or for all products by using Product Actions

1. Modify product titles individually

To change an individual product title, use the left-hand menu to select "Products --> On My Deal" 


Then, locate the product you wish to modify and click on the product title (as shown in the screenshot below) and enter the desired product title you require. NOTE: If you sell on multiple marketplaces this will change the title on all marketplaces.


2. You can also create different Product titles for groups of products using Product Actions

See this article