Hi @crypto.piotr,
STO creates the opportunity for the everyday investor to have a (small) say in large companies. Many company shares are not available to the public and only to bigger institutional bodies such as banks or financial investment companies. Hence my friend, I support your move to establish STO. Tokenization will reach more investors eventually.
If I recalled correctly we did discuss about Polymath, the STO issuance platform. I have no idea whether they are the non-responsive team you mentioned, but placing ERC-20 tokens is not a good choice. Fierce competition, high commission and basically the cons outweigh the benefits.
I came across a platform known as OwnMarket, a permission-less? blockchain. They moved away from the previous CHX tokens which were Ethereum based. Check out some more information here: https://medium.com/ownmarket/top-five-use-cases-for-the-own-platform-6a2e27a24f10
Also feel free to drop me an email. I should be able to do some digging to assist you, now that my PhD thesis is completed. All the best, @tysler :)