I was just going to suggest the 2HP RND, cos it just sits there taking up so little space but you can get Random gates out of it so can be used as an On/Off switch on things like the Freeze button on Clouds etc. Plus Smooth and Quantasized (stepped) random outputs you can use to Modulate your Modulators etc.

But @eexee's suggestion of the 4MS sounds like loads of fun.

BTW, if you happen to own a Disting it has a Chaos mode.

Enjoy your spare HP, don't rush to fill every last space, this is not like filling sticker books. Resist the urge to 'complete' your rack, its never complete so just relax.

https://youtube.com/@wishbonebrewery