The location of the loop will have no effect on how hard the pump works, at
least not that can be measured. The easy location, close to the pump, will
have minimum backflow and will be ideal. Only possible drawback I can see
is that the engine heat will make the little rubber flapper in the siphon
break dry out and need replacement slightly sooner. This isn't the big deal
it would be with sewage. Even if it leaks a bit, you probably would never
notices.

Go for it.

Roger