When using Shopify Flow for scheduled delivery, it is unlikely that you will only need to deliver to 100 customers. Therefore, you will need to add some ingenuity to the flow process by using "customer tags" and "recurring settings." For example, here is an example of setting up a schedule to deliver once a month.
Example of settings for scheduled email delivery with Shopify Flow when there are more than 100 recipients in one delivery

[Setup Method 1] Create a workflow to send emails on a schedule

[Setting method 2] Set the number of targets for the workflow schedule created in 1

[Setup Method 3] Create a workflow to delete tags of customers who have already received the delivery in preparation for the next month's delivery

