The context has changed and made most of this ticket obsolete.

First, LatLonPoint and related classes in Lucene are now in the core, not in the sandbox (https://issues.apache.org/jira/browse/LUCENE-7314). They are thus supported to the same extent as other core features.

Second, the precision of LatLonPoint seems largely sufficient for most use cases. From the javadoc of org.apache.lucene.document.LatLonPoint:

Values are indexed with some loss of precision from the

original double values (4.190951585769653E-8 for the latitude component

and 8.381903171539307E-8 for longitude).

In the worst case, for latitude, this gives a precision near the equator of 40,075.017/360*8.381903171539307*10^-8 = 9.33 cm, or around 3.7 inches. I'd say this is enough to find the location of a pizza joint or a rental bike, or for most use cases we're likely to encounter.

So, let's just add some documentation about the precision, that should be enough.