StaticArrays.jl is just linear algebra operations for tuples, and they have always been stack allocated as they are immutable and have a size known at compile-t

StaticArrays.jl is just linear algebra operations for tuples, and they have always been stack allocated as they are immutable and have a size known at compile-time, so Julia 1.5 will not bring anything new for it. The deal with 1.5 is that the GC has improved in that it does not require structs with references to dynamically allocated objects to be heap allocated themselves.