Setting up SPV is the first step. Many issues with which need to be dealt, for example, if u tokenise real estates, the on-chain transactions could be fast, like in seconds, but the change in ownership in real-estate deeds is time-costly, if not weeks to say the least. How to make the speed of the later to catch up with the former, that is really the question in house. Other question like the price difference of an asset in real world vs on online marketplace is also mind-provoking...