What i have experienced is it uses the form last input unless: a hero is no longer in your "real" form. To make sure, i usually make changes to real form, then CW form and upload.
ie; I had Flavi in 1st sub, but now i have KT, but CW form last upload had Flavi, if you look the space will be empty. So upload current or put Flavi back.

P.S. If you make improvements during CW, for those to show i do believe you need to upload again.