BG several of your points are valid however you fail economics 101. The tax assessment is an expense. If you increase expenses the number units people are willing to make available for a given price falls. As you see in the other thread, homes the would be rental with low assessment will be sold to owners at higher prices
Less units means more competition for the units and greater increases.
While a renter turn buyer does remove one renter from the pool, the effect on the pool of available rentals will be greater than the affect on the decrease of renters. As less SFRs are available to rent, there rental cost will increase, which will in turn pull the next leg down in size/quality up.
We’ve seen repeatedly how quickly rents rise with any constraint in supply in SoCal.
