I still think that depends a lot on your individual circumstances.
If internet data volume and internet bandwidth is an issue (e.g., you live in a rural area and rely on satellite broadband) and if you fly several times in the same area before going somewhere else a large cache size could help. In that case a large rolling cache saves the inconvenience of reconfiguring the manual cache when moving on.
Same internet situation and usually flying in one specific favorite area is where manual cache really makes sense since there is less need for manual reconfiguration.
And if internet data is not an issue a large cache is less necessary no matter where and how you fly, and I think that is where sizing cache based on RAM starts making sense.