Received an error when trying to create a scratch org that we have exceeded the limit of 25 rollup summary fields for Case. We have 31 such fields but Salesforce bumped us up to 35 some time ago. This has not been an issue when creating sandboxes. Also, while Contact Limits and other object limits have a line item for Rollup Summary Limit in a scratch org (with 25 available), there is no line item at all under Case.
I can't find a scratch org configuration setting that might address this.