The Befaco Out is a good price, especially if you don't mind doing a little soldering https://www.modulargrid.net/e/befaco-out-v3 / https://www.thonk.co.uk/shop/befaco-output-module/
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.
Sweelinck and EuroBadger