I adapted the bash shell 5.3 to more easily handle tasking. Each command & has its output gathered into lines and each line is tagged and send to the output with a preamble. The bash input stays on the command line and you can type command lines, select history, anything, even while the background tasks output appears above that:

  [ping:1:2814536:59] 64 bytes from ...: icmp_seq=58 ttl=113 time=28.7 ms
  [bash:0:2814530:9] samiam@samiam-h-pc-2:~/projects/basht$ ll *.md
  [ls:7:2814564:1] -rw-rw-r-- 1 samiam samiam  9790 Aug 10 15:01 basht_plan.md
  [ls:7:2814564:2] -rw-rw-r-- 1 samiam samiam  3921 Aug 10 15:43 README.md
  [ping:1:2814536:62] 64 bytes from ...: icmp_seq=61 ttl=113 time=26.8 ms
  [bash:0:2814530:10] samiam@samiam-h-pc-2:~/projects/basht$

Other that the task adaption, it is stock bash and can be substituted for regular bash.

Did you propose adding this capability to bash with the project maintainer(s)? If so, what was their response? If not, why not?

PS this can work with any shell, not just bash.

I sent the maintainers a message about it yes. I'll leave that up to them how to respond. I can see pros and cons to incorporation. I'll look forward to that discussion. Frankly I'd be thrilled if they did adopt it. In the meantime it's a usable fork of bash.

Thanks for the question.