I found mongod, geo search using big polygon feature CRS didn't accept the CRS I expected.
I expected:
"urn:mongodb:crs:strictwinding:EPSG:4326"
... where EPSG:4326 is the well-known legacy CRS identifier for WGS84 data.
But only this value for CRS worked:
'urn:mongodb:strictwindingcrs:EPSG:4326'