Let 'Request Time Criteria' be used even for fallback/backup recommendations
That said, if a premium recommendation is used with a Request Time Criteria and only returns lets say 2 out of 8 products based on criteria for Product Category. The backup recommendation that will kick in won't use the time criteria from the primary recommendation which will lead to show complete other products.
The benefit from this would be that one can use only one recommendation for many type of emails, rather than creating product category specific recommendations with similar backups. Time-saving and efficient.