We absolutely know how important this is to our users and are actively working on it. GDPR is a very large topic, so there are a number of angles from which we need to address this from.
We do our best to read as many posts in the forum as possible, whilst still working on Glide 
. Sorry if it seems like we’re not listening sometimes.
Right now, you can put together an onboarding experience with Glide (using tab visibility, forms etc). But we hope to have a fully custom solution for you soon.
In regards to data retention/deletion, a solution for this is a little further off – but we are working on it.