Your Markdown files are not uploaded to PX7 Digital.
Sync reads and writes the local folders and iCloud Drive location you select. File transfer between your Macs is handled by Apple iCloud Drive. PX7 Digital does not receive your Markdown files, folder contents or the generated setup/settings.md.
The app stores folder paths and preferences locally in macOS settings. The generated setup file in your chosen iCloud location records computer names and local folder paths so you can understand the configuration on each Mac.
License activation sends the license key, app identifier and a one-way device identifier to the PX7 license service. Update checks request the public update manifest. Purchases are processed by Stripe under its own privacy policy.
Contact PX7 Digital with privacy questions.