You are right of course – Park-4 is safer and still offers the same precise levelling option as Park-1.
As to WHY the second target was off, perhaps there is more than just one imbalance. You may need to shift your OTA along in its saddle, if you attach your camera AFTER levelling the axes, or don’t use a small, OTA front end counterweight, to compensate for this. If the clutches on the old AP-1200 or AP-900 aren’t “sufficiently” (but not excessively) tightened, slewing to a new target gives it enough time, and force from acceleration, for either axle to slip just a bit, and then all the previous careful levelling is for naught.
AP’s wonderful mounts are rugged and very powerful – they can carry huge loads - but an imbalanced OTA can easily cause either axle to slip. You will then be doing more RCAL’s, to compensate for missed targets all through the night.