I do think a “hybrid” component may be somewhat practical.
Every N posts in a topic you insert a “paginator”
Post 1
Post 2
...
Post 15
[*Page 1*] [Page 2] [Page 3] [Page 4]
Post 16
...
De-infinite scrolling Discourse is not a practical exercise, but a component that makes a “hybrid” paginator (even with topic list changes) is probably in the 2k-5k range.