I just put out a new release of TXR, which has a change that can reduce the nesting.

In pipes, you can now bind variables that are in scope of later pipeline elements.

  1> (flow "/usr/share/dict/words"  ; start with this path
       (file-get-lines)             ; get content as list of lines
       (let lines)                  ; bind lines variable to this list
       len                          ; take length of list
       rand                         ; get pseudo-random in [0, length)
       lines)                       ; index into lines
  "subdues"