Update 30/05/22: this feature has been implemented in our staging environment and is currently undergoing final testing. Due to be deployed in our next release.

Update 08/06/22: This feature has been implemented and you can now send multiple Cardano assets (Cardano tokens and NFTs with or without $ADA) in a single transaction.

To do this, select Send $ADA (from the Asssets or Accounts screens) and then click 'Add assets' at the bottom. You don't need to include $ADA in the transaction if you don't want to.