It would be useful to be able to batch create invoices and apply to many customers at once. E.g. registration fees to all customers
This is possibly not exactly the workflow you require, however this is how the application handles batching.
Create a memorised invoice for each relevant customer ie ones who belong to a particular group such as Monthly fees.
Create a memorised group.
Add the memorised transaction to the group.
Note: You can have the group as a standing order, or set to Don't remind me so you can trigger the group manually.