Another reason I have not laced 'heads in' to date radial.. is I suspect inbounds are more susceptible to 'head slap' on hard impacts. Whereas outbound's tend to contact the hub at a pt.. methinks minimizing said head slap. [?].

Head slap being my term for the spoke de-tensioning and then subsequent re-seating with a jolt when the spoke goes slack... again with the hard impacts.

I now use always.. Sapin Strong butted on all inbound rears. All Sapin Strong on rear triplet lacings.