Donations csv download does not show custom form answers

The donation widget allows a custom form to be added however the answers to this form are not visible from the .csv download from the Donation panel - any clues why this is the case? Most of my website designs are for non-profits and they need to collect some information from the donors so its super critical. 

I have not used the Donations Form, but I was having a similar problem with a commerce form, and aggregating promo codes and other information.

I used a premade scenario on www.make.com to "Save New Squarespace Orders to Google Sheets" and then one to "Create Mailchimp Subscribers from New Google Sheets Rows".

It's the long way round Robin's barn, but it gets the information I need where I need it to be.