NavList:

Frank,

Thanks for your remarks.

"... as inexpensive computation became available in the past forty years, suddenly we have options, and the "new" popular (popularized?) definition of a conjunction frequently asks for smallest angular distance"

100 % agree here. As much earlier discussed, and since we now have such computation power at our fingertips, this new "smallest angular distance" trend makes sense since such definition pertains to a mathematical invariant, irrespective of the reference system in use, whether equatorial, ecliptic or other.

 "But for visual angles seen by observers on Earth, ..."

I do not think that we should publish something "geocentric" here at least regarding planets [partial] overlapping, since - as for Lunars - the topocentric exact configuration is Observer's position dependent mainly because of parallax. A different story here, especially if we are to include refraction as well as Geoid shape. Nonetheless, if there is some geocentric overlapping of both planets, at least it will be maintained - even if a grazing one - for the sub-planets position on Earth. So, anytime there is even a geocentric grazing overlapping, there is at least one point on the Earth surface where there a grazing overlapping too. As a conclusion, restraining oneself to only geocentric computations remains meaningful - and is not misleading in a topographic sense - since any geocentric [grazing] overlapping will boil down into some [grazing] overlapping seen from at least one point of the Earth surface.

Kermit