I do have to make some changes on the feeds since my current company has added vendor designations before the SKU, ie for Apollo they have A-SKU. But the feeds do NOT have that designation before the SKU. They have a program where it automatically looks within that vendor's files and then adds the inventory and images. Let me know how you can handle that issue.
We have prefixes to be configured in the settings to handle SKU differences between the source file and the store. So if the source file has SKU ABC123 and the store only has SKU 123, so the prefix here is ABC. For example, it will matchmake/find the matching by removing the ABC.
To include postfix, you need to add $ after the value.
For example, the SKU in the store is 12345MAN and in the feed file is 12345
Then you need to include MAN$.