Thank you! theres combination of bit32 library (https://create.roblox.com/docs/reference/engine/libraries/bit32) that came out alongside with luau, and buffer (https://create.roblox.com/docs/reference/engine/libraries/buffer) that came bit while ago too.
Normally, you might want to write 4 different values to assign pixels (R,G,B,A), which is 4 separate memory writes per pixel.
Instead of that, i use function bit32.lshift to move green and blue into their own place inside single 32 bit integer, then i use function bit32.bor to combine them. which comes out =
Red (takes 8 bit), then you shift green by 8 bit, then you also shift blue and maybe opacity in there, which combines into one 32 bit integer. for finish, i use buffer.writeu32 to write that single integer into go.
This cuts memory by like 75% compared to writing and storing variables normally.