Apparently, since hwloc Version 2.4 lstopo seems to have a --cpukinds option. And in 2.6 they have specifically worked on distinguishing high and low performance cores for M1 mac’s, see hwloc/NEWS at master · open-mpi/hwloc · GitHub . I’ll take a look and will try to update Hwloc.jl accordingly tomorrow.
(Update: https://github.com/JuliaParallel/Hwloc.jl/issues/57)