Roadmap comes with customer features and cart functionality which is used on both Plus and non-Plus stores.
If you receive an automated message saying that "A cart transform function has failed" - this may related to the fact that you have a bundle for sale but a variant or product included in this bundle has been deleted.
This is not something that apps like Roadmap can stop website admin doing i.e. deleting a product or variant being used. This error can simply be avoided be ensuring that no actively used variants or products are drafted, archived, deleted, or removed from a sales channel.
In a nutshell - this comes down to good housekeeping.