For all of California's huge dysfunctions (which are frequently the side-effects of its huge successes), this is a good example of what the state gets right.
To people who are freaked out that this is going to turn into the opening scenes from Pixar's "Up", more often than not, in suburban areas, this will just result in a few dwellings per lot, imagine 2-3 town homes on what is now a .25 acre single family lot.
The 20% affordable component of Builder's Remedy means you need to propose at least 5 homes so one of them can be affordable.
That said, a "missing middle" program is a really helpful thing to help cities get their Housing Element into compliance so if you think there is a place where this density would be helpful, send a comment to your city council and cc HousingElements@hcd.ca.gov.
Perhaps it's less lucrative, but it would still allow for increasing the housing stock without putting a 50 unit building in the midst of an existing SFH neighborhood. Developers will also need to weigh the desirability of what they build into the equation. There's quite possibly a sweet spot of desirability and affordability at 3 dwellings per lot.
As an example, I live on a multi-dwelling lot (effectively town-homes without shared walls) in a predominately SFH neighborhood. It's very high density by California standards, but it's quite desirable and not apartment-block style living.
Unfortunately, many California cities are so incredibly far behind what's actually needed for equitable housing costs that the only practical way for them to catch up is a lot of 50-unit buildings built yesterday.
To people who are freaked out that this is going to turn into the opening scenes from Pixar's "Up", more often than not, in suburban areas, this will just result in a few dwellings per lot, imagine 2-3 town homes on what is now a .25 acre single family lot.