Hello,
I apologize for the issue you faced with internal site search spam last year. When switching from Yoast Premium to Rank Math Pro, you’ll find that Rank Math offers a feature to help combat internal site search spam.
Rank Math allows you to enable or disable the indexing of search result pages, which can help prevent unwanted internal search functions that could be exploited for spam. By navigating to Rank Math SEO → Tiles & Meta → Misc Pages in your WordPress dashboard, you can enable the Noindex Search Results option to prevent these pages from being indexed.
Here is a screenshot to guide you on how to enable this setting:

Enabling this setting can assist in blocking unwanted internal search functions that may lead to spam issues on your site.
If you have any further questions or need assistance during the transition, feel free to reach out to our dedicated support team, available 24/7, 365 days a year.
Thank you for considering Rank Math Pro as your SEO solution. Let us know if there is anything else we can help you with.
Best regards,
Sources:
Is Your Site the Victim of Internal Site Search Spam? » Rank Math
Why Rank Math Is Better Than Yoast » Rank Math
I saw that as an option, but I was hoping for a few more options when it comes to internal searches.
Hello,
At the moment, we don’t have that kind of feature. If that is something we can add in the future, we will surely let you know.
For now, the steps shared by Rankbot should help you eliminate the internal search spam: https://rankmath.com/kb/internal-site-search-spam/
Don’t hesitate to get in touch with us if you have any other questions.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.