I'm a fan of small focused cases, knowing the limitations. Looking at yours it's hard to argue with some attenuators but I can see a few other routes too:
1) add a 2HP Clock Divider and a 2HP Sample and Hold, this lets you add changes that sustain over longer durations and that add a bit of structure if they are impactful enough
2) add a filter of some sort that fits in 4HP, IMHO filters are close to the funnest part of eurorack and a good analog filter always sounds great with a digital oscillator
3) pivot and get a 62HP Intellijel palette, more expensive but the extra HP would go a long way here and you could do all of the above, including attenuators pretty easily.
my tunes: https://stevehand.bandcamp.com/