Wanted: Tips or Tools for creating sitemaps and indexing 50-100k unique URLS

I've been doing SEO for a couple decades and this is a first for me. I've had sites with large sitemaps: 500, 1000s pages before. But this site I'm working on CliqRex has 100k± urls/pages indexed for different movies, tv shows, podcasts, and more and I don't have a solid system for creating these sitemaps. I tried a few paid and open source tools that crawled the site but they all seemed to time out, stall, or not do a great job. I ended up creating a partial solution inside the website where I build the sitemaps. Do you have any tools for indexing 50k, 100k, or more URLs before I continue writing a solution in the site? Also, what best practices do you use for breaking down different sitemaps and schema? Does it matter if the same link exists in multiple sitemaps? Thanks!