The ideal visitor tracking on Covid-19

Since the Malaysian government allowing conditional movement order (MCO), every restaurant visitors need to write their name on a single paper. This lead to many digital initiatives to kick off QR scanning in a way to speed up checkin process for the public.
The state of Selangor came out a simple way for the public to checkin, which you can find it here.
This also based on my one of my similar project with the state government, compelling me to write about the ideal QR checkin product.
We also have since

There are two types of checking in.

A. Existing user scanning from government app.
B. New user scanning from their phone without any app.

User with existing government app :
1. Open existing app and click scan.
2. Scan QR.
3. All info is autofilled, and check in!

Users scanning QR code with their phone :
1. Open up phone QR scanner.
2. Scan & fill the form. This would be one time process as each additional scan user won't need to refill the form.
3. Checkin!
4. Next scan, no form, done.