Interesting question for you folks. Can I create a file in illustrator with several different shapes and then save as or export to a .csh file to import into photoshop? Doing it one by one is time consuming. Same question about creating files to be brushes for phothshop.
Copy them from Illustrator
Create a new canvas in Photoshop to hold them all
Paste them as Paths to different layers or separate them by layers etc.
Then use the Direct Select tool - right click and Define Custom Shape.
As far as I know CSH files are unique to Photoshop - you can create them in Photoshop - but I don’t know of any other program that can create them.
It’s possible maybe to write a script that does this
Copies your selection from Illustrator
Pastes each to a new layer in photoshop as paths
selects each and path on each layer
then define a new Custom Shape