Redirection like this doesn't seem to work if it comes first on GNU bash 5.0.17(1)-release.

For documentation purposes, this is the exact thing I tried to run:

    $ < <(echo hi) while read a; do echo "got $a"; done
    -bash: syntax error near unexpected token `do'

    $ while read a; do echo "got $a"; done < <(echo hi)
    got hi

Maybe there is another way...