Its quite a lot of fun.
2hp Bell for sound.
Befaco Burst for triggers and probability.
2hp ARP for Arpeggios.
Divkid / Instruo Ochd+ Expander for modulation.
Veno-Echo for delays and messing.
Monsoon Clouds for a bit of Reverb.
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.