Can stdout/stderr of a running process be dynamically redirected in FreeBSD ?

Imagine the situation when there is a process that is running in the 
terminal and periodically printing something related to its progress.

At some point this terminal output should be replaced by a TUI in the 
same terminal that would capture the original process' output and show 
it in its TUI sub-window, and would also show some other info.


There is the project for Linux called "redirect" that does such 
stdout/stderr redirection: https://github.com/jerome-pouiller/reredirect/

However, it uses ptrace functions that are missing in FreeBSD, like 
PTRACE_POKEUSER.


Is it possible to perform the action like is described in the first 
paragraph in some other way, given that ptrace doesn't have required 
functions?


This function is useful in many business contexts, when users run some 
long-running tools, and there is a variety of ways how results of these 
tools can be displayed to the user.



Thanks,

Yuri