Nothing breaks. Bar, line and pie charts stay free forever; their exports carry a small “Made with Chartmeister” watermark. A one-time license unlocks all 18 chart types and removes the watermark. No subscription, no account.
Both paid plans are lifetime licenses with future updates included: Single User is $69 once for 1 user on up to 3 devices, and Team is $199 once for up to 15 users.