I can appreciate, as Da Flex, posted that not writing down was to help prolong the life of MicroSD cards but could a switch be added to allow it to happen?
<memorysize>0</memorysize> Just click the link and read...
I was talking about A/V streaming buffer, because you didn't mentioned a specific buffer. Kodi's default setting includes Samba caching into RAM. Maybe you have to increase the "memorysize" parameter to keep the whole Samba cache in RAM.