Re: Stray from VFR flightplan
I'll jump in with an answer, but you must read it with caution as different rules and procedures apply in different countries... IMHO you can manoeuvre as much as you like between waypoints on a VFR FPL in unregulated airspace, there is no requirement to proceed in a series of direct lines... just make those waypoints at the time you specify (within tolerances).
Of course the problem comes if you get into difficulty and need tracing. From your airspeed it should be clear that you have not proceeded on a direct track... but call ATC if available. Tracing action will always consult your arrival and departure airfields, if ATC is not available, tell someone there your intention before departure...