How to change one component only of org-calc-default-modes?

Question

I'd like to change the setting of "calc-float-format" within "org-calc-default-modes", while avoiding to setq all of them like in:

(setq org-calc-default-modes
      '(calc-internal-prec   12
        calc-float-format    (float 12) ; [default: 8]
        calc-angle-mode      deg
        calc-prefer-frac     nil
        calc-symbolic-mode   nil
        calc-date-format     (YYYY "-" MM "-" DD " " Www (" " hh ":" mm))
        calc-display-working-message t))

I don't understand the format of that list: not an association list; weird beast.

Is there a way to do the above?

Answer 1

Easy:

(setcar (cdr (memq 'calc-float-format org-calc-default-modes))
        '(float 12))

Also:

(plist-put org-calc-default-modes 'calc-float-format '(float 12))