I have updated my tests with index_branch r1810 and these are the results:

	1 tile map	2 tiles map	9 tiles map
POI search	Yes	Yes	Yes
Cities
Accented characters	Yes	Yes	Yes
Existing city	Yes	Yes	Yes (1)
Existing region	Yes	Yes	Yes
Existing country	Yes	Yes	Yes
Combinations of city, region, country	Yes	Yes	Yes
Streets
Existing street+city	Yes	Yes	Yes (2)
Non existing street+city	Yes	Yes	Yes (2)
Only street	Yes	Yes	Yes (2)
Send to device	Yes	Yes	Yes

(1) All places within a given tile are assigned the same (wrong) country, e.g:
<node>
is_in=Soria, Castilla y León, Spain, Europe
name=Abion
place=village
</node>
Search city Abion -> Abion, CASTILLA Y LEÓN, BASQUE COUNTRY

(2) Missing all streets beginning by "Calle" before "Calle Real ..."
Occurrences of "Calle ":
1 tile: 4694
2 tiles: 4694+15206=19900
Previous round of tests 2 tiles map had the same problem with number of "Calle "=47770

Apart from search related issues, in the 9-tiles map routing is broken and also all tiles touching the sea are flooded. I have tried different combinations of options, but always the same result.