Support Memory up to 16GB In RouterOS V6 like RouterOS V7
Don't hold your breath.
Personally I'd much rather see MT devs focus on V7 advance than to try to backport everything to V6. BTW, RAM support is about kernel used in ROS and V6 uses ancient kernel. Possibly 32-bit only (on all platforms, including ARM used in CCR2xxx and CRS3xx) and without support for PAE, which then limits kernel to 4GB RAM, of which (depending on HW platform and particular kernel config) 1-2GB are dedicated for mapping of peripherial devices memory. Back in time (probably still true for current V6 kernel) not all device drivers were PAE-safe so compiling kernel with PAE support was sort of hazardous act, you never knew what's going to explode (and when). Correct approach is to provide 64-bit ROS for HW platforms supporting it and that comes with large RAM support automatically.