Missing viewZenithMean, viewAzimuthMean values near scene borders - workaround?

Dear all,

we have recently encountered a problem that biophysical parameters such as LAI, FAPAR, CWC, or CCC return NaN values near the edges of Sentinel 2 scenes. We found that the reason is that they all use the viewZenithMean and viewAzimuthMean parameters in the calculation, which are provided in a resolution of 5x5 km and are not available for the edges of individual scenes (see triangular shapes in the attached image). That is inconvenient because a request for a site located within such an area returns data for indices like NDVI but not for biophysical parameters.

I assume this is a known issue, so I wanted to ask if maybe someone came up with a workaround solution, (ideally) applicable directly within respective custom scripts.