Thanks very much for the reply. I had found the src for the multi_dim_bc_operators already but the info on compose is very handy.
I noticed however the performance is not what i would like it to be. I will respond later with a concrete example.
I do get this warning however is this of any significance?
┌ Warning: #= C:\Users\siemd\.julia\packages\DiffEqOperators\z4eVP\src\derivative_operators\convolutions.jl:419 =#:
│ `LoopVectorization.check_args` on your inputs failed; running fallback `@inbounds @fastmath` loop instead.
│ Use `warn_check_args=false`, e.g. `@turbo warn_check_args=false ...`, to disable this warning.
└ @ DiffEqOperators C:\Users\siemd\.julia\packages\LoopVectorization\kVenK\src\condense_loopset.jl:825