If you like to push your Subaru but are concerned about LSPI, then HPL offers their Premium Plus PCMO with HTHS above 3.5, which is something you won't find from any other manufacturer.
Within their HP line, Redline has the Euro 5W-30 and Euro 5W-40 with HTHS 3.6 and 4.3. They are SP in the same way as HPL. Their "standard" HP 5W-30/40 are .1 higher both but not SP.
Amsoil SS also has a 0W-40 and 5W-50. HTHS of 3.76 and 4.45, both SP. ...but i think you(who now seems to be gone) mean either a 30 or 40 wt..