It seems like you're using up a lot of hp with your compressor and mixer. Although I imagine you'll be using the Roland 531 as your main mixer, it's handy to have several submixers in your system. Perhaps you intend to use the Doepfer A-130-8 as a submixer, but the Frap Tools 321 and Intellijel Triplatt (listed below) offer many useful features in addition to mixing.
For a smaller compressor, you should look into:
Steady State Fate - Autodyne [4hp] https://www.modulargrid.net/e/steady-state-fate-autodyne
Noise Engineering - Librae Legio [6hp] https://www.modulargrid.net/e/noise-engineering-librae-legio
Cosmotronic - Messor [8hp] https://www.modulargrid.net/e/cosmotronic-messor
God's Box - Lollipop mk2 [12hp] https://www.modulargrid.net/e/god-s-box-lollipop-mk2
For submixers I really like:
Frap Tools - 321 [6hp] https://www.modulargrid.net/e/frap-tools-321-
Intellijel - Triplatt [6hp] https://www.modulargrid.net/e/intellijel-triplatt
Joranalogue - Mix 3 [6hp] https://www.modulargrid.net/e/joranalogue-audio-design-mix-3
A possible alternative to the Roland 531:
AI Synthesis - AI007 Quad Mixer [12hp] https://www.modulargrid.net/e/ai-synthesis-ai007-quad-voltage-controlled-mixer-vca
Toppobrillo - Minimix [14hp] https://www.modulargrid.net/e/toppobrillo-minimix-black-panel
Cosmotronic - Cosmix [16hp] https://www.modulargrid.net/e/cosmotronic-cosmix
Good luck and have fun!