I pose a meta resampling question: what is the optimal resampling spatial resolution for S2A data for ingestion within the biophysical processor for LAI output? Since most bands (B3 through B8a, B11, B12) used for vegetation applications have a spatial resolution of 20m, I would say this would be an optimal resampling resolution; however one could argue that all bands at some point are used to get to the end product of LAI, I presume, so resampling at 60m would be the optimal choice for this argument. The goal of obtaining the highest spatial resolution of 10m given that 1/3 bands are used for vegetation applications could be an argument as well.
I would lean towards resampling at 20m, given that 2/3 of the vegetation bands are acquired at this resolution, it strikes a good balance between resolution and processing time and would be easier to defend if questioned based on the aforementioned statements. I would like to hear others thoughts on the matter.