A couple thoughts that I hope are helpful, from another Palette user..
3 filters in a system of this size is probably too much. Pick one, or one plus the 2hp module. Remember that Plaits has a built-in LPG, too.
You have two dedicated ADSRs and two dedicated LFOs here, which is ok... but you might also find yourself happier with one solid multi-function module like Intellijel's Quadrax or XAOC's Zadar or Mutable's Stages. Especially given that 6hp for a non-VC ADSR is not the greatest use of space (the Pittsburgh module). Any of these options could potentially save you a couple hp, too.
Steppy seems like a mistake, given that you have a DrumBrute and KeyStep at your disposal. It is only a gate sequencer, not a CV sequencer, so it won't do you much good with this setup, really. I'd suggest replacing the Steppy with some other utilities: an attenuator/mixer (Intellijel's Duatt or Quadratt), and nonlinearcircuit's 1u Sloth module (great modulation source, and probably best bang for the buck in 1u modules). With the space you have leftover, you could still add a couple of other smaller 1u modules.
If you can make room, Pamela's New Workout is just a great workhorse for any small setup. 8 clocks, or LFOs, or envelopes, or Euclidean sequencers, or etc. etc. All with built-in attenuators, offsets, and more. If this were my setup, I'd cut both of your current LFO choices and replace them with PNW, unless you really need the VC.
Others will tell you (correctly) that this case is too small for a starter system... but you can always buy a bigger case later, and use the Palette for when you want to travel, so you can't lose. Enjoy!