Overall IMO it looks solid. Lots of "no regrets" modules there IMO.
A few things you may want to add sooner or later:
-- an output, like you said. IMO it makes a rig a lot easier to use, having an output that can go to headphones, DAW, etc.
-- XOAC Batumi, Mutable Stages, or something similar, just to give you more normal CV
-- 4MS SISM or something similar, to help you constrain CV to usable ranges. IMO this is very important
-- I would also want a quantizer in this rig. You're planning to use O&C, which should be fine. I like a dedicated one like Scales
Overall I think your rack above looks solid and fun. And its great you're leaving case room and have given thought to further adds.
Good luck, enjoy!