Today I received an answer from Arduino Technical support:
Ignacio Herrera (Arduino)
Oct 29, 2020, 9:10 GMT+1
Hello Remko,
Thank you for contacting Arduino Technical Support.
Your project is really interesting. This custom sensor feature is not available thus Arduino is unable to offer support to develop it.
I suggest you wait for other user interested in the project to reply and assist you with it. You can also reach out on Discord Arduino server, maybe you find partners there too.
I hope this was useful.
If you have any further issues or queries, please do not hesitate to contact us again.
I am Valentina, Product Manager of the Arduino Science Journal. Thanks for posting this here.
We are currently working on the release of other important features that will allow you to better work and handle data. After that we would consider your request. We are a small team working on it, but we will look into your request and consider it for future implementation. We have something similar coming soon, so stay tuned!
Also, if you would like to contribute to the Science Journal the app is open source! Also we would consider having you as a beta tester if interested. You can contact me via DM here on the forum.
Thanks! For the project (educational, I'm a teacher) I was working on I managed to get something working in a hacky way, that I'm still planning to share on projecthub.
For the next class / project where I'll use Science Journal I'll dive into the improvements.
Of course I'd like to test the beta! (I'll DM you.)
The Science kit includes the MKR WiFi 1010, right? So does this mean that the app offers more options when it's connected to a MKR WiFi 1010? Do you know why it was chosen to not yet offer this for the Nano33BLESense pins (yet)?
The app is great by the way. My students enjoyed working with it!