Although this is a nice security addition to wallets, this might not be that helpful especially to those who are lazy or those who don't understand why screenshot protection features are in place. Other than the fact that this could also be disabled or overridden by another application, others might simply take a pic at the seed phrase.
Another feature that needs to be disabled is allowing you to copy your seedphase to your clipboard, Most wallet allows you to copy your seedphase to your clipboard at a single click and the first thing that comes to mind after copying it is to save it up in your notepad or somewhere in your mobile device. I guess part of the consideration to take while choosing a wallet should be to check out for how concerned they are for the security and safety of her users. If they are negligence with users safety like the case with trust wallet that recommends users to backup her seed phrase on cloud, it's certainly a red flag to be mindful of.