-2 years of analysis of crypto ecosystem - probably resulting in this https://sonajin.io/Whitepaper-1290-articles
-then analysis of the community feedback in Q4 2018
-then another user feedback in Q1 2019
-and then yet another review in Q4 2019
Looks like these guys (or guy) love feedbacks, analyses, and reviews
Also, the project isn't (and probably won't be) open source
https://sonajin.io/FAQ-1292-articles
Specifically to prevent hardforks, if anyone can run a node then it is easy to copy, counterfeit and hardfork coins such as the case with almost all of the major coins. We value and respect the spirit of opensource community and some of our team members are members of this community, but we cannot guarantee the security or integrity fo the chain if anyone can run a node. One of the key ways fraud can occur is if enough nodes broadcast false transactions as is currently possible with most other currencies, we aim to stop this from being possible in the first place.
Thanks for your comments tomkat and thanks for checking out our project. We do value feedback and we do think it is wise to carefully plan Sonajin and our apologies if it wasn't more clear in the initial 2 years of research and planning in the road map. The reason feedback is so valuable is for the long-term success of a coin which we feel is going to be marked by trust and community involvement. Part of that aspect is incorporating as much of the community's feedback as possible into our vision for revolutionizing cryptocurrency.
You are also correct about the OpenSource aspect. The wallets will be OpenSource but as we mentioned, our hybrid-proprietary blockchain can only be fully secured against attacks by not allowing strangers to run nodes. If there does become a way in the future to make the node side OpenSource we would be glad to do it, as this would reduce our task of managing so much hardware and computing power on the backend side. The downside to public nodes is inherent increased risk and overall decreased transaction capability. However, we see a long-term benefit for the user side as everyone can focus on using Sonajin to buy and sell products and services without worrying about the traditional problems with other currencies.