My favourite screenshot tool is the camera on another phone.
In short, this limitation is rather pointless.
According to other comments in this thread, this just freezes when switching apps, and fails. I'm not too surprised, given that the feature (at least on Android) is meant as a security measure (i.e. most of the banking and 2FA apps use it to some extent).
But my personal favorite is that this is entirely, 100% client-side, and there's already a few handy ways to patch out the checks from the foss client.