When experimenting with different shelf or elevated rest configurations, the arrow's dynamic spine will change due to the variety of offsets from the shelf, side plate, and interaction with the nocking point height on the string. In other words, you may end up with the wrong arrow per configuration, ranging from subtle to just plain wacky-off.
This explains some of the poor arrow flight issues during these switches, even when moving towards a more advantageous riser configuration.
Unfortunately (or fortunately for the tinkerers) you might need to calculate for and obtain a different shaft for the new configuration. The step-forward brings a temporary step-back with the arrow and must be attended to with a re-tuning process. However, the end result of more accurate shooting negates this temporary detour's inconvenience.
Not always when the changes are minimal ... but sometimes.
Also, with a more extreme adjustment, say from shelf to elevated rest, the eye is now witnessing a different sight picture which requires a bit of time to recalibrate within the brain to achieve consistent and stable to-the-target arrow flight. It's hard to judge a change by just shooting a couple of shots. A session would be more instructive to allow the brain time to process the changes.