So if this requires a demo to use, are you writing the TF code manually?
The reason we have a read-only demo is because of the friction required to set up an account (you have to link your cloud account and repositories); we felt that the read-only account was the easiest way to take a look at the features without needing to go through the account creation process.
This is the real product I'd pay for. The networking world has plenty of awesome tools that let you just log in to prod, make the change you need, and an automated system comes along later and dumps the configs to source control and documents the changes. Let engineers move quickly and change stuff in prod, you update the terraform and keep everything synced in dev/test/etc.