I would like to see the Sale page presented and explained in advance. This would eliminate a major source of error. In the rush, it is stressful when you want to act quickly, but sees the page for the first time in front of him and also does not want to make mistakes when buying. So time passes unnecessarily or mistakes can happen (like here with the vouchers).
If the sale page with its rules (such as that all vouchers including bonus packs are automatically set) is known and everyone knows how and where to click when the page opens, then everyone who has prepared and really wants to buy immediately can make his purchase within a minute at the latest.
Then there should be a clear cut between Pre Sale and General Sale.