Automator recipe to speed up backups in Time Machine
launchd

Use launchd to run your two commands at specific times. By placing a launchd job in /Library/LaunchDaemons you can avoid needing sudo as the command can be run as root with this location.

See a launchd tutorial for getting started with launchd and step by step guides.

Determining whether Time Machine has finished must be handled by a script. The simplest solution is to re-enable low priority throttling at a specific time.

Third Party Tools

Alternatively, you can use a wide range of third party scheduling tools on macOS. These include the one I work on, Power Manager, which can run scripts at set times each day as root.