However, I find it difficult to believe the definition of flight time in this context is hardto understand. The issue is obviously to do with personal experience to retain currency, which must obviously be flight time undertaking a role that is both legal (as P2 in a SEP isn't) and credibly provides that experience.
In principle I tend to agree as a first reaction, but get immediately into trouble when defining borders. If a right seat pilot takes control he/she gains more experience then a left seat PIC staring at the autopilot for hours. Consequently one must exclude hours under A/P from being logged as PIC time, or would A/P cruise not qualify, but on APP or in traffic circle yes? I do see the strict regulation PIC in single pilot GA equals to exactly and one pilot only from T/O to LDG as a reasonable way out (let "you take control" totally regardless for logging hours - even if you are "in control" the PIC stays "in command").