Filtering the result on the report definition that incorporates the business logic criteria like SLA is less than deadline should enhance performance. So, the more filters that pair down the results, the less results the activity has to process.
I assume that the result set is fixed by whatever filter criteria are used, so the post processing will just have to deal with whatever the query returns. Again, the performance of the query will depend on the indexing on the filter columns, as well as the columns involved in join conditions if there are any joins. This is particularly true of large tables (and 200+ K records is starting to qualify as large).
Once you have created the report definition, you should have your database people run the query and generate an explain plan for it. That will tell them what opportunities there are for optimizing the tables/columns in the database for the report to run as fast as possible.