I decided to play through reborn again and ran into an interesting situation.
After beating Taka for the first time, you're supposed to jump down a ledge (only way out of the battle area) and encounter Heather. Knowing this, I decided to try and see if I could skip it. Because Taka's area has a bunch of grass I just fought random beedrill until my party passed out, which landed me back at the Jasper Ward center. I was now free to explore vine-less Jasper, move on to Beryl, anything I'd normally be able to do, with Heather still present in her preset event location.
That said, has anyone else experienced this? If so, will this affect my game? Is this just going to result in an oddly-placed sprite (which will be hilarious by the time the 'find heather' quest hits), or does this fail to trigger some important event flag?
Either way, I'll keep people updated on this.