Default output resolution for reproject.thumbnails is half of the input map

[axf295]

If I use reproject.thumbnails(imap,pos,size_deg) I would expect to have an output map of size_deg x size_deg with resolution equal to the input map.

but by default if res is not specified it uses input map res / 2

https://github.com/simonsobs/pixell/blob/4424302202f6978144e11e6d7bb7b378ebfcf78e/pixell/reproject.py#L60C3-L60C71

[msyriac]

@amaurea can confirm but I think this is expected behavior as its safer to interpolate to a finer geometry.