modis-43A4-061 STAC item footprints cause bbox search to miss overlapping granules

[amullen01]

STAC bbox searches against modis-43A4-061 can fail to return granules whose footprints intersect the query bbox, resulting in mosaicked images with only partial coverage of the bbox. This is particularly common when the search bbox intersects with a MODIS tile boundary. This appears to stem from catalog item geometry/bbox being coarse WGS84 bounding boxes that do not align with the MODIS sinusoidal tile grid.

Environment
Collection: modis-43A4-061 (MCD43A4.061)
STAC API: https://planetarycomputer.microsoft.com/api/stac/v1
Client: pystac-client with planetary_computer.sign_inplace
Loader: odc.stac.stac_load
Minimal reproduction

ROI (WGS84 bbox) near the h10/h11 sinusoidal tile boundary:

bbox = [-106.3706, 48.6672, -106.1583, 48.8076] 
datetime = "2020-07-08/2020-07-08"

search = catalog.search(
    collections=["modis-43A4-061"],
    bbox=bbox,
    datetime=datetime,
)
items = list(search.items())
# Returns only h11v04 granules (e.g. MCD43A4.A2020190.h11v04.061.*)
# Does NOT return h10v04, even though the ROI lies in h10v04 sinusoidal space

Granule	modis:horizontal-tile / modis:vertical-tile	STAC footprint intersects ROI?	Actual pixel coverage of ROI
h11v04	11 / 4	Yes (footprint fully contains ROI)	~26%
h10v04	10 / 4	No	~75%

Observed behavior

• h11v04 matches the bbox search but provides incomplete coverage.
• h10v04 is not returned despite covering most of the ROI.

Current workaround is to enlarge the search bbox or specify which MODIS granules to use.