Performance in Lua and design considerations:

• Optimisation Tips: http://lua-users.org/wiki/OptimisationTips

• Object Benchmark Tests: http://lua-users.org/wiki/ObjectBenchmarkTests

• Is these Lua performance tips still accurate? https://old.reddit.com/r/lua/comments/1142xw/is_these_lua_performance_tips_still_accurate/

• Lua: performance of __index as a function vs as a table: https://stackoverflow.com/questions/4355450/lua-performance-of-index-as-a-function-vs-as-a-table

• Performance overhead using __index? https://lua-l.lua.narkive.com/mtyoYFYg/performance-overhead-using-index

• 3 Different OOP approaches: performance, memory consumption, and aesthetics: https://devforum.roblox.com/t/3-different-oop-approaches-performance-memory-consumption-and-aesthetics/1601163

• Function call is expensive! https://forums.solar2d.com/t/function-call-is-expensive/322922

• Some performance issues fixed by Luau: https://luau.org/performance