I am building a site that will be based on a custom post type with 20 fields and we are expecting at least a 1,000 records submiited by members - the search section will have 9 criteria - a mix of select drop downs , text and checkbox fields
Hello. Thank you for contacting the Toolset support.
The thing is that as many frontend filters you will add to your view, it will have impact on performance. As at the end we will require to display filters with all required values and values will be fetched from database and hence it will have impact on performance when you add more and more filters.
You should not display all 1000 posts at once as thats not a feasible solution, even if you exclude Toolset and try to display 1000 posts with WordPress it will fail to load or take too much time to load the page as to display 1000 posts on single page is too much.