Hello everybody.
I'm new in this forum, a new Sequential customer, but not new to the world of synths and I am amazed that so few have noticed this lack.
It's not only a problem for the filter as "fourth oscillator".
If you play wide intervals with a long glide and your filter has a high tracking value, when you go up, it switches bright at once and, vice versa, when you go down, it becomes abruptly dark.
This could be a particular effect, but not a normal behaviour.
I studied the manual thoroughly looking for a solution, but it seems that there's not.
I got the idea that each oscillator has its own lag circuit, but the filter doesn't.
(Old analog gear had a single lag circuit on the CV bus, so everything attached to it behaved the same way.)
Hope that those lag circuits are pieces of software and not hardware related, so a future upgrade could fill the gap.