There, the user will have to paste some words (2-4) in random positions to confirm that the user did backup the phrase and to check if the backup is correct.
For the trouble of backing up, forcing people to backup IMO has more advantages than disadvantages; people familiar with non-custodial wallets will surely back it up regardless whether it's forced or not, then people who have no idea of a seed phrase will be forced create a backup before they can create a wallet, the issue in the OP wouldn't have happened if this was the case.
Educating the user is good but not all people read what's written in the notes, if the backup procedure is "forced" and they can't proceed, they may as well read what's written in the warnings.
For "testing purposes", I'll just copy paste it to a txt file for easy access, it's not too much of a hassle.