For now I believe he does it like I described in my previous post, by using the patch bay at the back, but through self patching (no external gear). Here is a proper step by step:
From an init patch :
1 Assign LFO 1 to (for example) VCO1 Metalizer with a max amount
2 Using the back panel, plug in VCO1 Metalizer CV OUT to the Gate Input
3 Set LFO 1 to sawtooth, Tempo synced, retrig mode OFF
4 Assign LFO 1 Rate in the matrix using the free assign buttons
5 Patch Seq Mod in LFO 1 Rate with a positive amount
6 Patch Velocity in LFO 1 Rate with a negative amount
7 Write a sequence in the sequencer
8 Using record mode, while stopped, use the big knob above the matrix to add positive seq mod values on the steps you want start to ratchet on
9 Add accents on the steps you want the ratchet to stop
NB : You will need to find the right modulations amounts on steps 5 and 6 (I don't recall the precise values, but it was kinda tricky to get it right)
In the end the whole setup felt not super super handy, so I am not completely sure that is the exact same technique he is using. However, the result was, to my ears, definitely similar.