Custom mounts

Neverwinter Nights 1 Custom Content
1

Hello everybody.

I would like to create custom mounts by using these creatures:

  1. https://neverwintervault.org/project/nwn1/hakpak/original-hakpak/custom-content-challenge-june-2018-monsters-asian-mythology
  2. https://neverwintervault.org/project/nwn1/hakpak/original-hakpak/custom-content-challenge-july-2017-all-things-aerial

What I did:
Set the integer bX3_IS_MOUNT to 1 on the creature.
Set the integer X3_HORSE_TAIL to the corresponding number in tailmodels.2da.
This works at his best on modeltype F (full) based creatures.

The problem.
90% of the creature are modeltype S (simple) based creatures: this means that once mounted, the creatures appear completely rigid in game.
Any way to convert them to modeltype F or other suggestions?

Thanks,
Milla