Cellular Growth Physics Simulation

I have been trying to develop a 3D cellular growth model based off the physics described in this paper by Andy Lomas -www.andylomas.com/extra/andylomas_paper_cellular_forms_aisb50.pdf
The algorithm seems to be buggy. Is there a better way to debug the physics. I understand the extent of the simulation will be limited in terms of processing power since it is not being computed on GPU. But I think it might be a good way to test out the physics on a small scale, say about 10-100k cells.

App link : -

The goal is to use only forces to 'naturally ’ create organic forms.