Why doesn't cons25 have cs in termcap info?

[Kitche]

Since some ports actually need cs(change_scroll_region) to run for example
tmux is one. I believe tmux does not change the term correctly which could
be the issue as well. But according to the author the term needs cs to
even run.

I m just wondering why cons25 is missing this from it's termcap, since
I've been working on adding it to cons25 so that some ports will work
correctly.