Tbh I cant see how changing your oil more often can have a bad effect on your engine life.
Simply put. Your engine creates friction with all the bits going up and down and round and round.
This causes microscopic bits of metal flakes to drift about in your oil and this becomes an abrasive causing
even more friction, leadin to even faster wear... An engine change significantly reduces this abrasive effect.
One thing that can lead to faster engine wear is over/under filling. OR NOT FILLING AT ALL
Over filling causes exsessive crankcase presure. Im not sure of the effects of this, but is a well known fact that
over filling is AS bad as under filling.
Under filling leads to exsessive wear, higher engine temp and finally engine damage.
The correct way of filling a Zoomer, "and I'm not saying you done this wrong ofc, just as a reference", is when filling
up the oil level, the level is checked by only holding the dipstick to the crankcase WITHOUT screwing it in at all.
Level can then be anyware between the top and bottom marks of the stick.
The 600 mile change wont harm your engine, but the maual does suggest a change at round 2000 miles.