@Laurens van de Venn Thanks for reaching out. The maximum number of Logic App app service plans (WS1, WS2, or WS3) that can be hosted in a resource group or subscription depends on the subscription limits and quotas set by Azure. These limits and quotas vary depending on the type of subscription you have.
We don’t have any limitations for Standard plans as of now unless there is a resource crunch at the region level.
Limits and configuration reference guide - Azure Logic Apps | Microsoft Learn
Please let me know incase of further queries, I would be happy to assist you.