stevea (2019-05-13 17:57:05+00:00): Andy, these are not tweet-length discussions.  They require more than a few words, so I use them.  As I address your questions, but risk (or engage in) loquacity, I recognize I may try your patience, hence my early offer of an apology, perhaps better characterized as a warning of "lengthy reply ahead."  Either way, it shouldn't take anybody "all day" to read it, that's hyperbole, really, and I'm trying to stick to facts and truth and fully answer your question, not engage in hyperbole.

You again assert that "OSM doesn't care about local authority zoning."  In my opinion, this is patently false, given OSM's definition of landuse and how (in many, perhaps most cases) zoning logically maps essentially directly onto OSM's definitions of landuse.  Not only is that a simple semantic truth, this has been true the entire decade I've been in the project.  Even as our wiki definitions of landuse have "richened up" over the years, I have seen nothing that changes that, or even a discussion close to changing that (except this one, which I characterize as a not-entirely-surprising attempt/move towards such a rule change, as I've seen these before).  However, it doesn't seem to be applied map-wide, but (in this case) appears to be singled-out toward me.  Worldwide, OSM would be vastly more blank than it is now if contributors hadn't entered landuse polygons which accurately describe landuse.  The mere fact these may (or may not) have come from zoning data is wholly irrelevant to anything; a total red herring.  Why?  Because they accurately describe landuse as OSM defines it.

In your original question (first Comment) of "Is it really all farmland in OSM terms?" My answer was " Yes, it is as OSM defines it."  Do you agree or disagree?

Here (succinctly) are the differences between the two areas:

On 41172401, the owners of this property have rights to "timber production" (and as I mention, appear to have done so on about 15% of it, this area of felled trees is correctly denoted natural=grassland).  They have obtained a state timber permit, which tips landuse into one best described with the OSM tag "landuse=forest."

The owners of the property described by the large farmland multipolygon (adjacent to 411772401) have rights to farm their property, and some do, especially after they fell trees which would interfere with what most consider farmland (harvesting trees IS agriculture, though OSM better tags this landuse=forest as noted above).  However, some have NOT obtained state forestry permits to log the trees.  99 times out of 100 they WILL be granted these permits, should they apply, especially given the zoning of their land.  Some do, and orchards are planted, or vineyards are started.  Some don't, leave the trees, harvest the "downed wood" (without cutting, trees do "shed branches" in wood-productive ways) while in some, not all cases, also live in residences on the property in a residential manner.  This is agricultural landuse of a certain kind, similar to forestry, but not accurately described by landuse=forest (no chainsaws felling trees), so landuse=forest is distinctly not applied.  AND, the use of this land as "could grow orchard, could plant vineyards, could start greenhouse_horticulture..." is also extant here, whereas on other lands (which are zoned residential or industrial, for example), this is absolutely not the case, so this agricultural distinction is captured with OSM's tag of landuse=farmland.

(The maybe-1%-of-time a timber permit is not granted is if there is an endangered species in a creek below and the logging activity would create too much silt, for example.  BTW, I know this as steelhead salmon spawn in my backyard ocean-flowing creek and State Fish & Game simply draws the line at timber production on these after a fish census is taken).

Does that answer your questions?  Might I ask you to answer my single question above, please?  Thank you.