If I was to do this, I'd decide on what audiences my site was targeting and ensure the landing page had pre-approved content for each of them. Then I'd only use the LLM to rearrange the pre-approved marketing content, such that it puts the content that it thinks best targets the visitor above the fold. This way, the worst the LLM can do is to order the content incorrectly, and the visitor would need to scroll to see the content that targets them.

Even better, the LLM can make up rules for matching traffic to targeted profiles (corp IPs shows enterprise content, gov IPs shows gov offering, EU IPs shows European hosting options, etc). This way you don't use an LLM while rendering the page, reducing cost and speeding up page load times.