Hi kristian,
To my knowledge, the FBX format can’t handle point amount changes. If there is a trick, I’m not aware of it.
The FBX format was developed as a format to store motion data (FilmBox).
You can animate the Tube that needs to open; the file is included. The FBX and the PLA folder need to be together.
Example:
https://www.dropbox.com/s/85i4lp9p6i30or6/CV3_2023_drs_22_ANef_02.zip?dl=0
Please note that this needs PLA (Point Level Animation), which I have introduced with the Cappucino function (Use the Commander to call it Shift+C). Note that the Deformer needs to be after that PLA “bake”
All the best