Maximum Number of Brushes

Something I only recently discovered is that the number bush groups you have open in the main panel, affects Scratch disk temp file size.  With huge groups like Kyles Megapack  having something like 700 presets, that can soon add up.  Try opening Photoshop with no documents open, and checking your primary scratch disk.

I have just done that and found a 5.2Gb file with nothing open, and just the Legacy and group with a few home made hair presets in it.

I can't imagine there being any limit on the number of unopened groups (the .abr files on your hard drive) other than drive space.

What I have done for many years now, is to rename the .abr files giving them meaningful names that work nicely in alphabetical order.  I generally find that I might use just two or three presets from a group, so I organise them into my own custom group giving the presets meaningful names as well.  So instead of trawling though four five water splash groups, I only load the one into the main panel.  I then use the search bar to find the presets I need.  Note:  I am not sure that search bar is turned on by default.

The search bar only looks at groups open in the main panel.