Concurrency Verified

✅ - A checkmark means "this has been tested, and will run concurrently". ❔ - The questionmark means "it hasn't been tested, safety unknown" ❌ - The red "X" means "this has been tested, and it will not work concurrently".

Here's how to perform a test:

1. Build dnscontrol with the -race flag: go build -race (this makes a special binary)

2. Run this special binary: dnscontrol preview with a configuration that lists at least 4 domains using Porkbun. More domains is better.

3. The special binary runs much slower (1/10th the speed) because it is doing a lot of checking. If it reports problems, the error message will indicate where the problem is. It might not be 100% accurate, but it will be in the right area.