First, thanks for all the tips I will test these approaches next few evenings/days.

In this case I would assume that Moi3D could serve the purpose quite well because when 3D printing the part it is not needed to have 100% smooth and organic shapes for the details. The 3D printed part will be surface treated (sanded, painted, coated) anyway. Below are a couple of examples when lure is modeled in Solidworks and 3D printed with FDM printer. With FDM printer it should be ok with hard edges for details because the resolution is still quite rough. This basically the tutorial I have been trying follow and figure out how to do it in Moi3D: https://www.youtube.com/watch?v=CYa1wiWgMDw&t=602s

I have also included 3dm file in this message. I this file I have been thinking about using Trim to project gills curves to the base model and I have also planned to model gills as a separate object and project that object with Deform/flow to the model.