As an artist with traditional background that loves doing digital art I think it would be really useful and would get a lot of new artist atention into Photoshop. The idea I want to propose is a brush randomizer that goes trough an array(in terms of software development) with various different brushes from one stroke to the next one. It would be really helpful becouse the traditional "randomness" is close but lacks a bit of random interferences in the perfection of digital art. For example a scattered brush would be set randomly by the script or custom brush with these features and the next stroke would be a more hard brush without the artist being able to predict or have to change to another brush to create the traditional feel of not 100% control.
Hope it can ve viable to develop, I think it would be an interesting and useful feature that not only photoshop but other painting softwares are lacking it.
Thanks for reading! If more detail is needed I can help or try to explain better.