We have created a Photoshop script that merges multilayer Photoshop files (or single-layer files: PSD, PNG, JPG...) into a single PSD file. Additionally you can import every PSD into a folder or all layers mixed up.
It cost just 3 bucks and you can download it from: https://bit.ly/3zYHFs4
Any feedback for new scripts or to improve the ones we already created is welcome.
Enjoy!
Sergio