Performance throttling to emulate PS4 / PS4 Pro from a PS5

As more creators move to PS5, there is an increasing need for them to be able to see how their creations run on the lower frame rates of the PS4 & PS4 Pro. Currently they have no way of knowing if their creation will run smoothly on the slower platforms, and therefore they cannot optimise for those platforms.

So it would be great if PS4 / PS4 Pro emulation modes would be available in PS5, primarily so a creator could see how their frame rate is suffering on the other platforms. Ideally a PS4 Pro creator would also have a PS4 emulation mode, although this is perhaps less critical (as the performance difference between PS4 & Pro is smaller).