Legal and tax related matters are so complicated, it is hard to standardized through any technology. It is because the interpretation of a tax or legal term can be different based on the situations. I don't think any start up has tried or even interested to solve this kind of issues yet.
This is the case when there is no legal framework. For a law to be in place, the guide must be there and for cryptocurrency, the whole emergence is yet to be backed up legally. So whatever law or regulation, because it is not inscribed in the constitution might not see the light of the day especially because the court won't be able to lay reference to the constitution.
If a governemnt try to bring in a new legislation relate to cryptos, they definitely have the guides and roadmaps available, but the wish has to be there! We already have Japan, Germany and Malta legalized the cryptos and issed necessary legal framework for their citizens, so guide is there!
But the question here is related to ICOs, whether a start up company will be interested in solving such complicated issue without much viability for business?? I belive no! Once a country lay the foundation for crypto legislation, then we can see some startups forming ti solve the tax related matter for their citizens and these startups may not float an ICO.
I really am not aware of any ICO that are solving legal and tax related issue. Please let us know if you know some ICOs working on the same field.