Choosing invokation of list in an interactive clause

[Heime]

Have made an interactive function that uses two parameter options.

I can either invoke list inside the let construct, or as alternative
outside it.  What would be the sensible one to choose ?

(defun ltxstix-integ-slup (grafm seltr)
  "Binary Operations with explicit slant and upright versions."

  (interactive
    (let ( (csel '("Symbol" "Command"))
           (cseq '("intsl " "iintsl" "iiintsl" "ointsl")) )
      (list
        (completing-read "Grapheme: " cseq nil t nil)
        (completing-read "Selector: " csel nil t nil) )))

      (do-this-and-that grafm seltr) ) 

Alternative

(defun ltxstix-integ-slup-altern (grafm seltr)
  "Binary Operations with explicit slant and upright versions."

  (interactive
    (list
      (let ( (csel '("Symbol" "Command"))
             (cseq '("intsl " "iintsl" "iiintsl" "ointsl")) )
      
        (completing-read "Grapheme: " cseq nil t nil)
        (completing-read "Selector: " csel nil t nil) ))) 

        (do-this-and-that grafm seltr) )