ıt ıs possible to see any pressure in 20" section (when drilling with 26" bit) ? and how much pressure (if it is not wildcat)?
if yes, u can use;

21 1/4” 2 M CHH
21 1/4” x 2M -13 5/8” 3M Casing Hanger Spool
13 5/8"3M-11"5M Spool

or ıf no,
u can cut 20" csg and u can start from directly 13 5/8” 3M CHH after 17 1/2" section.

U have various alternatives. If u write clearly what u want, ı can help u.

Regards,