I have a Happy Nerding filter with an 18db Low Pass, also as @Farkas says Doepfer do https://www.signalsounds.com/doepfer-a-103-18db-low-pass-filter-euroack-module-tb-303

I've recently built the combo of TB-O and TB-EFA for some proper 303 action which sound great and quite a bit different to my HNVCF's 18db, the HN is good but the TB-EFA is gnarly and bubbling https://www.modulargrid.net/e/ge0sync-synth-tb-efa

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