billing address skips delivery

i've added some custom fields to get more info on the deliver details (side question -- i'd love for those to be date and time fields specifically!)

however when you click the "My delivery and billing addresses are the same." on the billing screen, it skips right over the delivery details step leaving those two "required" fields empty.

if you "edit" to go back to step 3, it will then require them.

how do we fix this? can we have the "My delivery and billing addresses are the same." option COPY the info to step 3 without skipping it?

thank you!