My apologies, I’m only familiar with Illinois and Florida real estate law. A CA attorney should be able to answer that with a short, no cost phone consultation (if a trust can’t support such an arrangement, an LLC might).

If a company or other entity is owned by a single person and just owns a single piece of property, this does not work and California will not let the prop 13 tax rate stay with the company. You are obviously trying to cheat to get around the law. As there are more owners of the company and the company has more diverse holdings, California is less likely to insist on resetting the assessed value of the real estate owned by the company upon sale. One REIT buying another REIT is fine. Like many laws, one does not really know what they mean on the edges until you do something and are taken to court.