Neither the A4 or Analog Keys will “midi sequence” anything, with CV indeed their only external sequencing on their own abilities. The Analog Keys will only act as a midi controller at push of button while you still could have the AK sequencer running, but not driving anything via midi by sequencer.
There’s the original Waldorf Pulse Plus (only the ‘PLUS’ version) that has not only extensive midi implementation, but also extensive CV INS/OUTS, and also will work both ways as a CV to MIDI/MIDI to CV converter. Not sure if the expensive Kenton Box would do what you want with the Volca Bass or if the Volca is able to be circuit-bent like the Monotribe can be.
Really hoping with OverBridge, the ability for A4/AK to midi sequence at least bare minimum note data.