The signup list exists only to send launch updates about Biz Bollox and related Life Bollox announcements. It is not used for behavioural profiling, advertising audiences, or resale.
Signup entries are written to a server-side CSV file in the site storage area. That keeps the release simple, but it also means the hosting environment must be locked down properly and writable only by the web process.
The site loads Google Fonts from Google-hosted domains. Aside from that, the release does not depend on third-party trackers, ad scripts, or analytics bundles.
Keep signup data only as long as it is needed for launch communication. If you later move the list into a mailing platform, delete or archive the CSV copy securely as part of that migration.