I also compared VST2 and VST3 Avenger Vengeance plugin and it seems to be the same problem with the VST3 plugin.
VST2 works fine. It could be the way S1 handles VST3 plugins or it could be that its a general VST3 standard not implementing it.
I can confirm this. Can't say why it's like that. Don't know if it's the same in for example cubase.
FYI: Even if Arturia have synths where there are only one cutoff filter, and that's premapped to use the standard MIDI CC#74 for cutoff, then you can change that MIDI CC, if you wish to do so.
There are applications that have multiple cutoff parameters, but only one of them can be premapped to use CC#74. For example Modular V have up to 3 filters that each has cutoff parameters and CS-80 has 4 cutoff parameters.
Not all synths have MIDI CC#74 applied for cutoff by default, no matter it's software or hardware synths.
CC#74 is'nt a reserved parameter in Arturias applications.
BTW: You do know some of Arturias synths like for example SEM V has many sequenced modulation possibilties?