> It's better than the status quo
Without putting more thought into it, I don't know. I don't see how this changes the revenue picture.
> reduces the lost taxes to a far smaller number of units (every corporation and person vs some older people)
That is independent of the tax lien idea.
> It also allows older people to move without 'losing' a prop 13 tax benefit, since they can retain more value of the large house they don't need anymore with a smaller lower maintenance condo.
This I can see. I know Florida had issues with people who wanted to downsize but couldn't afford to because of the tax jump from selling their homesteaded property.
That said, I'm not sure this alone would open up enough inventory to actually reduce prices.