No worries
I would just like to say there is a person on discord @fabioattard made this plugin, he was gathering all event Flags/Works in one plugin... Not sure how far he gotten through. I think I uploaded my data and just got busy with life.
so GitHub - fattard/FlagsEditorEXPlugin: PKHeX Plugin for dumping and editing all sorts of internal flags
To answer your question:
Yes in Event Flags -> Research -> write the flag number
as an example Sky Trainer Colm 1857, (If you battled the trainer it can either be checked or unchecked, depends how the game reads it, mostly trainer battles are unchecked and when you battle/defeat them the flag changes to be checked.)
whatever value you got undo it/ reverse it (check -> unchecked, unchecked -> checked).
Press save after changing
Export .sav
use new .sav
*****Please keep a backup if you are not used to editing flags and constants