Hello Fancellu, and welcome to the forum.
Good question, you showed me that each preset has it's own MIDI excerpt! I didn't know that, I only knew about the blues demo on the top of the interface, which you can play by pressing the Play button on the top. That is always the same demo, no matter on which preset you are, as you've probably discovered.
I tried opening the Pianoteq plugin inside Reaper, playing a MIDI excerpt from within the preset manager, and recording at the same time in Reaper, but it didn't work. It may be that Modartt is willingly not giving access to these MIDI segments, since they get them from other players, like Phil Best, and others, who are not employees of Modartt, as far as I know.
So it is up to the providers of the demos, if they want to publish their own works in MIDI format. If you hover over the play button in the preset manager, you can see the names of the pieces played, unless they are improvisations.You can google the names, with the word MIDI added at the end.
Some of these demos might be on the Piano E-Competition website, and others in Shared files on this page. If not, and you can't find them by googling, then there is probably no way of getting them as MIDI, except contacting the creators!
https://www.piano-e-competition.com/mid...ctions.asp