Indeed, at the moment it's only a lowpass filter... It was like this in my "schematics source". But I will check it with other MS20 schematics!
I'm sure that many here already know this... In the MS20, the filter section was implemented as a pair of filters in series, with a 6dB/oct HPF followed by a 12dB/oct LPF. As I understand it, the two filters were "tuned" variants of the same design. This pair worked as a unit to create the classic MS20 sound. I appreciate that this is a different thing to providing an MS20-style filter.
A lot of current clones (and DIY schematics) provide for both halves - sometimes as two filters with a link switch, for example, and some as one individual filter with a HP/LP switch. For me, the most useful configuration is a twin-filter (one HP, one LP) with a link switch. Prices can get quite steep and that's something that we need to avoid here.
That final link has some other very interesting schmatics, but I imagine this is old news to a number of people here, I just hadn't seen it until I did a quick search. Oh yes, and for the super serious, this is an interesting paper: www.timstinchcombe.co.uk/synth/MS20_study.pdf
Overall, my point was more to understand what is being delivered, rather than request something different. If it was a switchable/pluggable module, I would have bought two. As it is, I bought just one, together with three other modules so that my rack configuration is now completely full. If it becomes a switchable module (or better a twin linkable one), I'll just have to buy another one and lose a module.