I found this map online, it shows the locations where you can find Maple in the past:
3 of the locations on the talus peak are surprisingly open, they are hard to reach though, especially if you don't want to trigger an encounter with Maple on the way there. They are potentially the best places though. These are the best locations to encounter her in the past
The screen east of the Lynna Village Shooting Gallery is very open if you remove all 20 cuttable bushes.
This is the map for the present with all locations where Maple can spawn:
There are three good spots in the Forrest of Time, though the north east one is the best. The south one has some cuttable bushes. The north one is the best place to encounter Maple, because it is somewhat accessible and very open
There is a good place on the Talus peak in the present, too, it is located at the same place as the most south one from the past (from the three good ones).
Both Maple locations on the Yoll Graveyard are good and open, the north one has 4 cuttable bushes.
There is one potentially good location is the south east screen of the Rolling Ridge Base (The same screen where she can appear in the past), it is impossible to reach without triggering Maple on your way there, unless you didn't yet fill the kill counter. It may be possible to do it with very targeted time manipulation, but it feels like doing so actually resets the counter (someone please confirm this).